A stall heating control method, device and vehicle

Abstract

The embodiment of the application relates to the technical field of new energy vehicles, and discloses a stall heating control method and device and a vehicle, the method comprising: in the case of receiving a stall heating instruction, obtaining a stall heating historical count value and a stall heating available cycle number; the stall heating available cycle number is used for representing the maximum execution number of a stall heating operation that can be executed by a motor, and the stall heating available cycle number is determined based on a full-life cycle number, a thermal aging cycle number and a thermal management function cycle number of the motor; in the case of the stall heating historical count value being less than the stall heating available cycle number, the stall heating instruction is responded to, and the motor is controlled to execute a stall heating operation to heat an energy storage unit. The application can reduce or avoid the probability of winding insulation failure of the motor of the vehicle caused by stall heating, realize active quota management of the stall heating function in the whole life cycle, and improve the reliability of motor operation and the safety of vehicle operation.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, specifically to a stall heating control method, device, and vehicle. Background Technology

[0002] In the field of new energy vehicles, the power battery, as the core energy source of the entire vehicle, directly affects the vehicle's range, charging speed, and power output due to its low-temperature performance. When the ambient temperature is low, the battery's internal resistance increases, its usable capacity decreases, and in severe cases, it may even be unable to charge and discharge normally. To solve this problem, the vehicle's thermal management system usually needs to preheat the battery. Among these solutions, using the heat generated by the motor in a stalled state to heat the battery has become a widely adopted battery heating technology because it does not require additional heating elements, has low cost, and high heat utilization efficiency. This solution uses a motor controller to keep the motor in a stalled state, causing the stator windings to generate Joule heat through a large current. This heat is then transferred to the battery pack through coolant circulation, thereby achieving rapid temperature rise.

[0003] However, during the long-term and repeated stall heating process, the stator windings of the motor will frequently experience large-scale temperature cycling shocks. These drastic temperature changes will cause cumulative fatigue damage to the winding insulation material due to thermal expansion and contraction, accelerating insulation aging and potentially leading to serious faults such as inter-turn short circuits or grounding breakdowns, endangering the high-voltage safety of the entire vehicle.

[0004] In related technologies, real-time heat accumulation within a single driving cycle or a preset fixed temperature threshold is typically used to determine whether to limit the heating power of the stall heater. This method only focuses on heat accumulation within a single stall heater cycle, and over the vehicle's lifespan, it can still lead to motor winding insulation failure, causing motor damage and other safety accidents. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this application is to provide a stall heating control method, device and vehicle, which aims to reduce or avoid the probability of motor winding insulation failure due to stall heating, thereby improving the reliability of motor operation and the safety of vehicle operation.

[0006] In a first aspect, embodiments of this application provide a stall-heating control method, applied to a vehicle, the vehicle including an energy storage unit and at least one motor, the method comprising: Upon receiving a stall heating command, the system acquires the historical stall heating count and the number of available stall heating cycles. The stall heating command requests the motor to perform stall heating operations. The historical stall heating count represents the number of times the motor has effectively completed the stall heating operation. The number of available stall heating cycles represents the maximum number of times the motor can perform the stall heating operation. The number of available stall heating cycles is determined based on the motor's total lifespan cycle count, thermal aging cycle count, and thermal management function cycle count.

[0007] If the historical count value of stall heating is less than the number of available stall heating cycles, the motor is controlled to perform stall heating operation in response to the stall heating command to heat the energy storage unit.

[0008] This application embodiment calculates the number of available cycles for stall heating in advance based on the motor insulation life model during the design phase. During actual vehicle use, the motor controller controls the enabling state of the stall heating function based on the comparison between the historical stall heating count and the number of available stall heating cycles. By directly binding the life prediction result with the function enabling condition, active quota management of stall heating cycles is achieved at the functional level. This avoids the problem of premature failure of the motor winding insulation system due to accumulated thermal stress from multiple stall heating cycles, which is caused by protection based solely on real-time heat accumulation or fixed temperature thresholds within a single driving cycle. This reduces the risk of inter-turn short circuits or grounding breakdowns in the motor.

[0009] In some embodiments of this application, the method further includes: Based on the vehicle's overall load spectrum, the motor's temperature cycle spectrum is determined; the temperature cycle spectrum includes the maximum temperature difference of the motor windings in one temperature cycle, as well as the number of temperature cycles. Based on the temperature cycling spectrum, the first target model, and the linear cumulative damage rule, the total number of cycles throughout the lifespan is calculated.

[0010] This application embodiment extracts the temperature cycling spectrum of the motor winding based on the vehicle load condition spectrum, and uses the Coffin-Manson model combined with Miner's linear cumulative damage rule to calculate the total life cycle number. This allows the calculation of the total life cycle number to reflect the cumulative damage suffered by the motor winding due to temperature cycling fatigue under actual use conditions, avoiding the life estimation deviation caused by using a fixed empirical threshold, and improving the accuracy of the total life cycle number calculation.

[0011] In some embodiments of this application, the method further includes: The thermal aging life of the motor winding insulation material is determined based on the motor's operating temperature under target conditions and the second target model. The number of thermal aging cycles is calculated based on the thermal aging life and the cycle duration of a single temperature cycle of the motor.

[0012] This application's embodiments calculate the thermal aging life of motor winding insulation materials under reliable operating conditions using the Arrhenius model, and convert the thermal aging life into an equivalent number of cycles. This allows the number of thermal aging cycles to reflect the thermal aging damage caused by continuous high temperatures in the motor winding insulation system under normal operating conditions, distinguishing it from temperature cycling fatigue damage. This avoids the problem of inaccurate life estimation caused by conflating different types of thermal stress, and improves the scientific accuracy of the thermal aging cycle calculation.

[0013] In some embodiments of this application, the method further includes: The number of cycles of the thermal management function is calculated based on the expected number of operations of at least one thermal management function of the vehicle, the temperature cycle amplitude of the motor winding during the operation of the thermal management function, the first target model and the linear cumulative damage rule.

[0014] This application embodiment statistically analyzes the expected number of runs and temperature cycle amplitudes of thermal management functions other than stall heating that are achieved through active heat generation via electric drive. It then uses the Coffin-Manson model and Miner's linear cumulative damage rule to calculate the number of cycles for thermal management functions. This allows the calculation of the available number of cycles for stall heating to isolate the occupation of the motor winding insulation life by other heat generation functions in the vehicle's thermal management system. This avoids the problem of overestimating the available number of cycles for stall heating due to ignoring the life occupancy of other thermal management functions, thus improving the accuracy of the calculation of the available number of cycles for stall heating.

[0015] In some embodiments of this application, the method further includes: The number of cycles available for stall heating is obtained by subtracting the number of thermal aging cycles from the total life cycle count, and then subtracting the number of thermal management function cycles.

[0016] This application embodiment calculates the available number of cycles for stall heating by subtracting the number of thermal aging cycles from the total life cycle count and then subtracting the number of thermal management function cycles. This method separates the thermal stress consumption during normal driving and the thermal management function usage in the motor insulation life, accurately calculating the available number of cycles for the dedicated stall heating function. This avoids the problem of imprecise life budget allocation caused by simply reserving a fixed margin, and realizes personalized allocation of the life budget for the stall heating function.

[0017] In some embodiments of this application, the method further includes: After the vehicle is powered on, the stall heating history count value stored in the vehicle's non-volatile memory unit is read; If the read is successful, the stall heating history count value is stored in the flash memory unit of the vehicle's motor controller; In the event of a read failure, the stalled rotor heating history count value is initialized to 0, and a corresponding exception flag is generated.

[0018] This application embodiment reads the stall heating history count value from the non-volatile storage unit after the vehicle is powered on, and stores the stall heating history count value to the flash memory unit when the read is successful for subsequent fast access. When the read fails, the stall heating history count value is initialized to 0 and an exception flag is generated. This ensures that the stall heating history count value can be reliably restored every time the vehicle is powered on, avoiding the problem of count value loss or returning to zero due to power failure, and ensuring the continuity of the cumulative count throughout the entire life cycle.

[0019] In some embodiments of this application, the method further includes: After the vehicle is powered on, the status information of the motor controller and the signal detection information of the motor are obtained; If either the status information or the signal detection information is in an abnormal state, the historical count value of stall heating will be set to the target maximum value; the target maximum value is greater than the number of available stall heating cycles.

[0020] This application embodiment sets the historical count value of stall heating to a target maximum value greater than the number of available stall heating cycles when the status information of the motor controller or the signal detection information of the motor is abnormal. This makes the system tend to be conservatively protected in abnormal states, avoiding the problem of the stall heating function being mistakenly activated due to signal abnormalities, which would consume extra motor winding insulation life and improve the safety of the system in fault states.

[0021] In some embodiments of this application, the method further includes: If the stall heating operation is successfully executed, the stall heating historical count value is accumulated and updated, and the updated stall heating historical count value is written to the vehicle's non-volatile storage unit. The stall heating historical count value is configured as a monotonically increasing integer.

[0022] This application embodiment accumulates and updates the historical count value of stall heating after the stall heating operation is successfully executed, and writes the updated historical count value of stall heating into a non-volatile storage unit. The count value can only increase and cannot decrease, so that every valid stall heating event is recorded in the total life cycle count value. Moreover, the count value is not affected by the vehicle power failure, avoiding the problem of the count value being lost due to power failure and thus failing to accurately reflect the actual consumption of motor insulation life, and ensuring the reliability of the total life cycle count.

[0023] In some embodiments of this application, responding to a stall-rotor heating command, controlling the motor to perform a stall-rotor heating operation to heat the energy storage unit includes: In response to the stall heating command, control the motor to perform stall heating operation; Obtain the operating power of the motor; If the duration of continuous operation with power greater than or equal to the power threshold reaches the target duration, the stall heating operation is determined to have been successfully executed. If the operating power is less than the power threshold within the target duration, the stall heating operation is determined to have failed, the heating command is abandoned, and the historical stall heating count value is not updated.

[0024] This application embodiment uses the duration during which the operating power is continuously greater than or equal to the power threshold reaching the target duration as the criterion for successful execution during the stall heating operation. This ensures that only stall heating operations that actually produce sufficient heating effect are counted in the stall heating historical count value, avoiding the problem of false counting when the operating power briefly reaches the power threshold due to signal jitter or instantaneous disturbances, thus improving the accuracy of the stall heating historical count value.

[0025] In some embodiments of this application, the method further includes: If the historical count value of stall heating is greater than or equal to the number of available stall heating cycles, the stall heating command will be abandoned and the stall heating function of the motor will be disabled.

[0026] This application embodiment abandons the response to the stall heating command and disables the stall heating function when the historical count value of stall heating is greater than or equal to the number of available stall heating cycles. This ensures that the stall heating function is permanently disabled after the cumulative execution count reaches the upper limit of the number of available cycles calculated based on the motor insulation life model. This avoids the problem of the motor winding insulation system failing prematurely due to the number of stall heating cycles exceeding the life budget, and fundamentally guarantees the service life of the motor insulation system throughout its entire life cycle.

[0027] Secondly, embodiments of this application provide a stalled rotor heating control device, which is applied to a vehicle. The vehicle includes an energy storage unit and at least one motor. The stalled rotor heating control device includes: The acquisition module is used to acquire the historical count value of stall heating and the number of available stall heating cycles when a stall heating command is received. The stall heating command is used to request the motor to perform stall heating operation. The historical count value of stall heating is used to represent the number of times the motor has completed the stall heating operation. The number of available stall heating cycles is used to represent the maximum number of times the motor can perform stall heating operation. The number of available stall heating cycles is determined based on the total life cycle count of the motor, the thermal aging cycle count, and the thermal management function cycle count.

[0028] The control module is used to respond to the stall heating command and control the motor to perform stall heating operation to heat the energy storage unit when the historical count value of stall heating is less than the number of available stall heating cycles.

[0029] This application embodiment calculates the number of available cycles for stall heating in advance based on the motor insulation life model during the design phase. During actual vehicle use, the motor controller controls the enabling state of the stall heating function based on the comparison between the historical stall heating count and the number of available stall heating cycles. By directly binding the life prediction result with the function enabling condition, active quota management of stall heating cycles is achieved at the functional level. This avoids the problem of premature failure of the motor winding insulation system due to accumulated thermal stress from multiple stall heating cycles, which is caused by protection based solely on real-time heat accumulation or fixed temperature thresholds within a single driving cycle. This reduces the risk of inter-turn short circuits or grounding breakdowns in the motor.

[0030] Thirdly, embodiments of this application provide a vehicle, including: Memory; Processor; and Computer programs; The computer program is stored in memory and configured to be executed by a processor to implement the method provided in the first aspect.

[0031] Fourthly, embodiments of this application provide an electronic device, including: Memory; Processor; and Computer programs; The computer program is stored in memory and configured to be executed by a processor to implement the method provided in the first aspect.

[0032] Fifthly, embodiments of this application provide a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the method as provided in the first aspect.

[0033] In a sixth aspect, embodiments of this application provide a computer program product, which includes a computer program or instructions that, when executed by a processor, implement the method provided in the first aspect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0035] Figure 1 Structural block diagrams of vehicles according to some embodiments of this application are shown; Figure 2 A flowchart of a stalled rotor heating control method according to some embodiments of this application is shown; Figure 3 Structural block diagrams of stall-heating control devices according to some embodiments of the present disclosure are shown; Figure 4 Structural block diagrams of electronic devices according to some embodiments of this application are shown. Detailed Implementation

[0036] The terms “first,” “second,” etc., are used for descriptive purposes only and have no sequential or technical meaning, nor should they be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. "Fixed connection" refers to a connection where the relative positional relationship remains unchanged after connection. "Rotary connection" refers to a connection where the two parts can rotate relative to each other after connection. "Sliding connection" refers to a connection where the two parts can slide relative to each other after connection.

[0038] In the embodiments of this application, "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0039] This means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 85 degrees and 95 degrees.

[0040] The term "electrical connection" refers to the flow of current or signal from one conductor to another. An electrical connection between A and B means that current or signal can flow from A to B and vice versa. This connection includes direct and indirect electrical connections. A direct electrical connection between A and B means that A and B are physically connected. An indirect electrical connection between A and B means that A and B are connected via C, where C can be at least one wire or device.

[0041] The embodiments of this application are described below with reference to the accompanying drawings.

[0042] Please see Figure 1 , Figure 1 Structural block diagrams of vehicles according to some embodiments of this application are shown, such as Figure 1As shown, the vehicle 100 includes a motor 102 and an energy storage unit 104. Exemplarily, the motor 102 is a permanent magnet synchronous motor or an AC asynchronous motor.

[0043] In some embodiments of this application, a stall-rotor heating control method is provided, which is applied to, for example... Figure 1 The vehicle shown includes an energy storage unit and at least one motor.

[0044] Figure 2 Flowcharts of stalled rotor heating control methods according to some embodiments of this application are shown, such as... Figure 2 As shown, the method includes: In S202, upon receiving a stall heating command, the historical stall heating count value and the number of available stall heating cycles are obtained.

[0045] Among them, the stall heating command is used to request the motor to perform stall heating operation, the stall heating history count value is used to characterize the number of times the motor has completed the stall heating operation, and the available stall heating cycle count is used to characterize the maximum number of times the motor can perform the stall heating operation. The available stall heating cycle count is determined based on the motor's total life cycle count, thermal aging cycle count, and thermal management function cycle count.

[0046] In this embodiment, when the vehicle is in a low-temperature environment, the temperature of the energy storage unit is below the suitable operating temperature range. The vehicle controller sends a stall heating command to the motor controller. The stall heating command requests the motor to perform a stall heating operation. After receiving the stall heating command, the motor controller first obtains the historical stall heating count value and the available stall heating cycle count. The historical stall heating count value represents the number of times the motor has effectively completed the stall heating operation. The available stall heating cycle count represents the maximum number of times the motor can perform the stall heating operation.

[0047] The available cycle count for stall heating is determined based on the motor's total lifespan cycle count, thermal aging cycle count, and thermal management function cycle count. The total lifespan cycle count characterizes the total number of cycles the motor winding insulation system can withstand due to temperature-induced fatigue throughout the vehicle's entire lifespan. The thermal aging cycle count characterizes the number of cycles consumed by the motor winding insulation system under normal driving conditions due to continuous thermal aging. The thermal management function cycle count characterizes the number of cycles occupied by other functions in the vehicle's thermal management system, excluding stall heating, that utilize active heat generation through electric drive over their entire lifespan.

[0048] S204, if the historical count value of stall heating is less than the number of available stall heating cycles, respond to the stall heating command and control the motor to perform stall heating operation to heat the energy storage unit.

[0049] In this embodiment, the motor controller compares the acquired historical count value of stall heating with the available number of stall heating cycles. If the historical count value is less than the available number of stall heating cycles, the motor controller responds to the stall heating command and controls the motor to perform stall heating to heat the energy storage unit. The motor controller keeps the motor in a stall state, causing the stator windings to generate Joule heat through a large current. By controlling the amplitude and phase of the current applied to the stator windings, the motor controller prevents the motor from generating effective driving torque, and all electrical energy is converted into Joule heat in the stator windings. Coolant flows through the cooling channels inside the motor housing, carrying the heat generated by the stator windings out of the motor and transferring it to the energy storage unit through the vehicle's thermal management circuit. After absorbing the heat carried by the coolant, the energy storage unit's temperature rises, its internal resistance decreases, and its usable capacity is restored.

[0050] During the stall heating operation, the motor controller continuously monitors the motor's operating status and compares the historical stall heating count with the available stall heating cycle count. When the historical stall heating count reaches the available stall heating cycle count, the motor controller stops responding to stall heating commands.

[0051] This application embodiment calculates the number of available cycles for stall heating in advance based on the motor insulation life model during the design phase. During actual vehicle use, the motor controller controls the enabling state of the stall heating function based on the comparison between the historical stall heating count and the number of available stall heating cycles. By directly binding the life prediction result with the function enabling condition, active quota management of stall heating cycles is achieved at the functional level. This avoids the problem of premature failure of the motor winding insulation system due to accumulated thermal stress from multiple stall heating cycles, which is caused by protection based solely on real-time heat accumulation or fixed temperature thresholds within a single driving cycle. This reduces the risk of inter-turn short circuits or grounding breakdowns in the motor.

[0052] In some embodiments of this application, the method further includes: Based on the vehicle's overall load spectrum, the motor's temperature cycle spectrum is determined; the temperature cycle spectrum includes the maximum temperature difference of the motor windings in one temperature cycle, as well as the number of temperature cycles. Based on the temperature cycling spectrum, the first target model, and the linear cumulative damage rule, the total number of cycles throughout the lifespan is calculated.

[0053] In this embodiment, the process of obtaining the available number of stall heating cycles for the motor controller first requires calculating the total lifetime cycle count of the motor. The motor controller or calibration tools used in the vehicle design phase determine the motor's temperature cycle spectrum based on the vehicle's overall load spectrum.

[0054] The vehicle load spectrum includes the motor torque and speed distributions under different driving conditions. These driving conditions include urban congestion, suburban, highway, and hill-climbing conditions. Based on the duration of each driving condition in the vehicle load spectrum and the corresponding motor torque and speed, the motor controller, combined with the motor loss model, calculates the heat generation power of the motor windings under each driving condition. The motor controller then calculates the temperature change curve of the motor windings based on the heat generation power and the heat dissipation power of the motor housing. Finally, the motor controller extracts the amplitude of each temperature cycle and the number of occurrences corresponding to that amplitude from the temperature change curve.

[0055] The temperature cycle spectrum includes the maximum temperature difference of the motor windings during one temperature cycle, and the number of temperature cycles. The maximum temperature difference is the difference between the highest and lowest temperatures of the motor windings during a complete temperature rise and fall. The number of temperature cycles is the number of temperature cycles with the same maximum temperature difference throughout the entire lifespan of the vehicle.

[0056] The motor controller calculates the total number of cycles over its entire lifespan based on the temperature cycling spectrum, the first objective model, and the linear cumulative damage rule.

[0057] For example, the first target model is the Coffin-Manson model.

[0058] For example, the first target model can be expressed by formula (1): (1) in, In the first i Temperature cycle amplitude The number of fatigue life cycles that the motor winding insulation material can withstand; C These are the material constants of the Coffin-Manson model, which are related to the fatigue resistance of insulating materials. For the first i The amplitude of a temperature cycle, that is, the difference between the highest and lowest temperatures of the winding in one cycle, which is also the maximum temperature difference mentioned above. m This is the exponential constant of the Coffin-Manson model, reflecting the sensitivity of temperature cycling amplitude to fatigue life.

[0059] The motor controller substitutes each maximum temperature difference value in the temperature cycle spectrum into the Coffin-Manson model to calculate the fatigue life cycle number corresponding to each maximum temperature difference value. The motor controller uses Miner's linear cumulative damage rule to calculate the total damage.

[0060] For example, Miner's linear cumulative damage rule can be expressed by formula (2): (2) in, For the total cumulative damage, when When the value is 1, it indicates that the insulating material has reached the end of its lifespan. n i In the actual vehicle load spectrum, the first i Temperature cycle amplitude The number of times it occurs; In the first i Temperature cycle amplitude The number of fatigue life cycles that the motor winding insulation material can withstand.

[0061] After obtaining the total cumulative damage Then, based on the total cumulative damage ,Sure When =1, it represents the total number of cycles that can be experienced, which is also the total number of cycles in the lifetime.

[0062] For example, the total number of cycles over the entire lifespan can be calculated using the following formula (3). : (3) in, Total cumulative damage; n i In the actual vehicle load spectrum, the first i Temperature cycle amplitude The number of times it occurs.

[0063] In practical applications, the modified Coffin-Manson equation can be used in motor controllers to improve calculation accuracy. The modified Coffin-Manson equation introduces an average temperature effect term into its basic form. This average temperature effect term characterizes the influence of the average temperature during temperature cycling on fatigue life.

[0064] This application embodiment extracts the temperature cycling spectrum of the motor winding based on the vehicle load condition spectrum, and uses the Coffin-Manson model combined with Miner's linear cumulative damage rule to calculate the total life cycle number. This allows the calculation of the total life cycle number to reflect the cumulative damage suffered by the motor winding due to temperature cycling fatigue under actual use conditions, avoiding the life estimation deviation caused by using a fixed empirical threshold, and improving the accuracy of the total life cycle number calculation.

[0065] In some embodiments of this application, the method further includes: The thermal aging life of the motor winding insulation material is determined based on the motor's operating temperature under target conditions and the second target model. The number of thermal aging cycles is calculated based on the thermal aging life and the cycle duration of a single temperature cycle of the motor.

[0066] In this embodiment, the target operating condition is the vehicle's reliability operating condition. The reliability operating condition is the typical operating condition of the vehicle under normal driving conditions. The motor's operating temperature under the target operating condition... T op The temperature is obtained through temperature sensors or calculated using a motor thermal model. The temperature sensor is located at the end of the motor stator winding and is used to detect the actual temperature of the stator winding insulation material.

[0067] For example, the second objective model is the Arrhenius model.

[0068] For example, the second objective model can be expressed by formula (4): (4) in, For constant temperature T op Below, the thermal aging life of the motor winding insulation material; A These are constants in the Arrhenius model, which are related to material properties and failure criteria. E a The activation energy characterizes the ease or difficulty of the thermal aging reaction of insulating materials; k Boltzmann's constant; T op This refers to the operating temperature of the motor under the target operating conditions.

[0069] The motor controller measures the operating temperature of the motor under target conditions. T op Substituting into the Arrhenius model, the thermal aging life of the insulation material of the motor windings was calculated. .

[0070] The motor controller calculates the number of thermal aging cycles based on the thermal aging life and the duration of a single temperature cycle of the motor.

[0071] For example, the number of thermal aging cycles can be calculated using the following formula (5): (5) in, This refers to the number of thermal aging cycles. The thermal aging life of the motor winding insulation material. t cycle This represents the duration of a single temperature cycle.

[0072] This application's embodiments calculate the thermal aging life of motor winding insulation materials under reliable operating conditions using the Arrhenius model, and convert the thermal aging life into an equivalent number of cycles. This allows the number of thermal aging cycles to reflect the thermal aging damage caused by continuous high temperatures in the motor winding insulation system under normal operating conditions, distinguishing it from temperature cycling fatigue damage. This avoids the problem of inaccurate life estimation caused by conflating different types of thermal stress, and improves the scientific accuracy of the thermal aging cycle calculation.

[0073] In some embodiments of this application, the method further includes: The number of cycles of the thermal management function is calculated based on the expected number of operations of at least one thermal management function of the vehicle, the temperature cycle amplitude of the motor winding during the operation of the thermal management function, the first target model and the linear cumulative damage rule.

[0074] In this embodiment, at least one thermal management function includes a low-temperature heating function for the power battery and a cabin heating function. The low-temperature heating function for the power battery generates heat through a stalled motor and transfers the heat to the power battery via coolant circulation, thereby achieving low-temperature heating of the power battery. The cabin heating function generates heat through a stalled motor and transfers the heat to the cabin heater core via coolant circulation, thereby achieving cabin heating.

[0075] Based on the vehicle's thermal management strategy, the motor controller calculates the estimated number of operations for each thermal management function throughout the vehicle's entire lifecycle. The estimated number of operations for the low-temperature heating function of the power battery is determined based on statistical data of the ambient temperature at the vehicle's location and user driving habits. The estimated number of operations for the cabin heating function is determined based on statistical data of the ambient temperature at the vehicle's location and user heating habits.

[0076] The motor controller acquires the temperature cycling amplitude of the motor windings during each thermal management function operation. The temperature cycle amplitude is the difference between the highest and lowest temperatures during the process of the motor windings rising from the initial temperature to the highest temperature and then falling back to the initial temperature when the thermal management function is running. The motor controller calculates the temperature change curve of the motor windings based on the motor's heat generation power and the heat dissipation power of the motor housing during the thermal management function operation, and extracts the temperature cycle amplitude from the temperature change curve.

[0077] The motor controller uses the first objective model, namely the Coffin-Manson model and Miner's linear cumulative damage rule, to calculate the equivalent number of cycles occupied by thermal management-related functions throughout their entire lifespan: (6) in, The equivalent total number of cycles occupied by all non-locked-rotor heating thermal management functions over their entire life cycle, which is also the expected number of operations of at least one of the above thermal management functions. i This serves as an index to represent different types of thermal management functions; For the first i The number of times thermal management functions are expected to operate throughout the vehicle's entire lifecycle; For the first i When the thermal management function is running, the temperature cycle amplitude generated by the motor winding is the same as the temperature cycle amplitude of the motor winding when the thermal management function is running. C These are the material constants for the Coffin-Manson model; m This is the exponential constant of the Coffin-Manson model.

[0078] This application embodiment statistically analyzes the expected number of runs and temperature cycle amplitudes of thermal management functions other than stall heating that are achieved through active heat generation via electric drive. It then uses the Coffin-Manson model and Miner's linear cumulative damage rule to calculate the number of cycles for thermal management functions. This allows the calculation of the available number of cycles for stall heating to isolate the occupation of the motor winding insulation life by other heat generation functions in the vehicle's thermal management system. This avoids the problem of overestimating the available number of cycles for stall heating due to ignoring the life occupancy of other thermal management functions, thus improving the accuracy of the calculation of the available number of cycles for stall heating.

[0079] In some embodiments of this application, the method further includes: The number of cycles available for stall heating is obtained by subtracting the number of thermal aging cycles from the total life cycle count, and then subtracting the number of thermal management function cycles.

[0080] In this embodiment of the application, after obtaining the total lifetime cycle count... Number of thermal aging cycles Thermal management function cycle count Then, the motor controller calculates the total life cycle count, subtracts the thermal aging cycle count, and then subtracts the thermal management function cycle count to obtain the number of available cycles for stall heating.

[0081] For example, the number of available cycles for stalled rotor heating is calculated using the following formula (7): (7) in, The number of cycles available for stall heating; The total number of cycles over the entire lifespan; This refers to the number of thermal aging cycles. This refers to the number of cycles for the thermal management function.

[0082] The motor controller will calculate the number of available cycles for stall heating. Round down to the nearest integer to obtain the number of available stall heating cycles. The motor controller uses this integer number of available stall heating cycles as a hard disable threshold for the stall heating function and writes it into its non-volatile memory. This hard disable threshold cannot be changed throughout the vehicle's entire lifespan.

[0083] This application embodiment calculates the available number of cycles for stall heating by subtracting the number of thermal aging cycles from the total life cycle count and then subtracting the number of thermal management function cycles. This method separates the thermal stress consumption during normal driving and the thermal management function usage in the motor insulation life, accurately calculating the available number of cycles for the dedicated stall heating function. This avoids the problem of imprecise life budget allocation caused by simply reserving a fixed margin, and realizes personalized allocation of the life budget for the stall heating function.

[0084] In some embodiments of this application, the method further includes: After the vehicle is powered on, the stall heating history count value stored in the vehicle's non-volatile memory unit is read; If the read is successful, the stall heating history count value is stored in the flash memory unit of the vehicle's motor controller; In the event of a read failure, the stalled rotor heating history count value is initialized to 0, and a corresponding exception flag is generated.

[0085] In this embodiment, after the vehicle is powered on, the motor controller executes an initialization procedure. The motor controller reads the stall heating history count value from the vehicle's non-volatile memory. The non-volatile memory is either an electrically erasable programmable read-only memory or a flash memory built into the microcontroller.

[0086] Upon successful read, the motor controller stores the stall heating history count value in its flash memory unit. The flash memory unit is a high-speed cache memory integrated within the motor controller. After loading the stall heating history count value from the non-volatile memory unit to the flash memory unit, the motor controller directly reads the stall heating history count value from the flash memory unit during subsequent operation.

[0087] In the event of a read failure, the motor controller initializes the stall heating history count value to 0 and generates a corresponding exception flag. Read failures include situations where the stall heating history count value has not yet been written to the non-volatile memory unit upon initial power-on, and situations where a non-volatile memory unit verification error prevents the stored stall heating history count value from being read correctly. The exception flag is recorded in the fault diagnosis flag bit of the motor controller. The motor controller reports the exception flag to the vehicle controller via a diagnostic message.

[0088] This application embodiment reads the stall heating history count value from the non-volatile storage unit after the vehicle is powered on, and stores the stall heating history count value to the flash memory unit when the read is successful for subsequent fast access. When the read fails, the stall heating history count value is initialized to 0 and an exception flag is generated. This ensures that the stall heating history count value can be reliably restored every time the vehicle is powered on, avoiding the problem of count value loss or returning to zero due to power failure, and ensuring the continuity of the cumulative count throughout the entire life cycle.

[0089] In some embodiments of this application, the method further includes: After the vehicle is powered on, the status information of the motor controller and the signal detection information of the motor are obtained; If either the status information or the signal detection information is in an abnormal state, the historical count value of stall heating will be set to the target maximum value; the target maximum value is greater than the number of available stall heating cycles.

[0090] In this embodiment, after the vehicle is powered on, the motor controller acquires the motor controller's status information and the motor's signal detection information. The motor controller's status information includes an initialization completion flag and a controller fault flag. The motor's signal detection information includes current feedback signals, voltage feedback signals, and temperature sensor signals.

[0091] The motor controller determines whether both the status information and signal detection information are normal. If either the status information or the signal detection information is abnormal, the motor controller sets the stall heating historical count value to a target maximum value. The target maximum value is greater than the number of available stall heating cycles. The target maximum value is the maximum value defined by the vehicle communication protocol. The vehicle communication protocol is either Controller Area Network Protocol (CAN) or Flexible Data Rate Controller Area Network Protocol (FDR). The target maximum value ranges from 0xFFF0 to 0xFFFF; for example, the target maximum value is 0xFFFE.

[0092] The motor controller sends the stall heating history count value, set to the target maximum value, to the vehicle controller via the controller area network. Upon receiving the stall heating history count value at the target maximum value, the vehicle controller determines that the available stall heating times have been exhausted and thus prohibits issuing stall heating requests.

[0093] Abnormal status information includes situations where the motor controller is in an incomplete initialization state and where a fault flag exists in the motor controller. Abnormal signal detection information includes situations where the current feedback signal is lost, the voltage feedback signal is lost, and the temperature sensor signal is lost.

[0094] This application embodiment sets the historical count value of stall heating to a target maximum value greater than the number of available stall heating cycles when the status information of the motor controller or the signal detection information of the motor is abnormal. This makes the system tend to be conservatively protected in abnormal states, avoiding the problem of the stall heating function being mistakenly activated due to signal abnormalities, which would consume extra motor winding insulation life and improve the safety of the system in fault states.

[0095] In some embodiments of this application, the method further includes: If the stall heating operation is successfully executed, the stall heating historical count value is accumulated and updated, and the updated stall heating historical count value is written to the vehicle's non-volatile storage unit. The stall heating historical count value is configured as a monotonically increasing integer.

[0096] In this embodiment, the motor controller responds to the stall heating command and controls the motor to perform the stall heating operation. If the stall heating operation is successful, the motor controller accumulates and updates the historical stall heating count value.

[0097] The motor controller increments the current stall heating history count by 1 to obtain the updated stall heating history count: IPU_MotorStuckTimes_new = IPU_MotorStuckTimes_old + 1; Wherein, IPU_MotorStuckTimes_new is the updated stalled rotor heating history count value, and IPU_MotorStuckTimes_old is the previous stalled rotor heating history count value.

[0098] The motor controller writes the updated stall heating history count value to the vehicle's non-volatile memory. The write strategy can be either an immediate write strategy or a cached write strategy. The immediate write strategy is suitable for memory cells with sufficient erase / write life, such as ferroelectric memory. The cached write strategy is suitable for electrically erasable programmable read-only memory (EROM), where the motor controller first caches the updated stall heating history count value in random access memory (RAM) and then writes it to the non-volatile memory in a concentrated manner when the vehicle is powered off.

[0099] After writing the updated stall heating history count value to the non-volatile storage unit, the motor controller performs a readback to verify the success of the write operation. If the readback verification is successful, the motor controller confirms that the stall heating history count value has been successfully stored non-volatilely. If the readback verification fails, the motor controller performs the write operation again and generates a storage fault flag when the number of consecutive write failures reaches a preset threshold. The preset threshold ranges from 2 to 5 times; for example, the preset threshold is 3 times.

[0100] This application embodiment accumulates and updates the historical count value of stall heating after the stall heating operation is successfully executed, and writes the updated historical count value of stall heating into a non-volatile storage unit. This ensures that every valid stall heating event is recorded in the total life cycle count value, and the count value is not affected by the vehicle power failure. This avoids the problem of the count value being lost due to power failure and thus failing to accurately reflect the actual consumption of motor insulation life, ensuring the reliability of the total life cycle count.

[0101] In some embodiments of this application, responding to a stall-rotor heating command, controlling the motor to perform a stall-rotor heating operation to heat the energy storage unit includes: In response to the stall heating command, control the motor to perform stall heating operation; Obtain the operating power of the motor; If the duration of continuous operation with power greater than or equal to the power threshold reaches the target duration, the stall heating operation is determined to have been successfully executed. If the operating power is less than the power threshold within the target duration, the stall heating operation is determined to have failed, the heating command is abandoned, and the historical stall heating count value is not updated.

[0102] In this embodiment, the motor controller responds to the stall-rotor heating command and controls the motor to perform stall-rotor heating operation. The motor controller obtains the operating power of the motor.

[0103] The motor controller compares the motor's operating power with a power threshold. The power threshold ranges from 3kW to 10kW; for example, the power threshold is 5kW. The motor controller determines whether the operating power is consistently greater than or equal to the power threshold. If the operating power is consistently greater than or equal to the power threshold, the motor controller starts timing to obtain the duration.

[0104] The motor controller compares the duration of operation with a target duration. The target duration ranges from 5 to 60 seconds; for example, the target duration is 30 seconds. If the target duration is reached when the operating power is consistently greater than or equal to a power threshold, the motor controller determines that the stall heating operation was successfully performed.

[0105] If the operating power is less than the power threshold within the target duration, the motor controller determines that the stall heating operation has failed, abandons the heating command, and does not update the stall heating historical count value. The motor controller terminates the current timing and returns to the state of waiting for the next stall heating command.

[0106] The values ​​of the power threshold and target duration are determined based on the heat resistance rating of the motor winding insulation material and the heating requirements of the energy storage unit. The higher the heat resistance rating of the motor winding insulation material, the larger the power threshold can be set. The more urgent the heating requirement of the energy storage unit, the shorter the target duration can be set.

[0107] This application embodiment uses the duration during which the operating power is continuously greater than or equal to the power threshold reaching the target duration as the criterion for successful execution during the stall heating operation. This ensures that only stall heating operations that actually produce sufficient heating effect are counted in the stall heating historical count value, avoiding the problem of false counting when the operating power briefly reaches the power threshold due to signal jitter or instantaneous disturbances, thus improving the accuracy of the stall heating historical count value.

[0108] In some embodiments of this application, the method further includes: If the historical count value of stall heating is greater than or equal to the number of available stall heating cycles, the stall heating command will be abandoned and the stall heating function of the motor will be disabled.

[0109] In this embodiment, the motor controller compares the historical stall heating count with the available stall heating cycle count. If the historical stall heating count is greater than or equal to the available stall heating cycle count, the motor controller abandons the stall heating command and disables the stall heating function of the motor.

[0110] The motor controller sets the stall heating function enable flag to the disabled state. The stall heating function enable flag is stored in the motor controller's random access memory. After disabling the stall heating function enable flag, the motor controller will no longer respond to any stall heating commands issued by the vehicle controller.

[0111] The motor controller reports to the vehicle controller via diagnostic messages that the stall heating function has been permanently disabled due to the end of its lifespan. Upon receiving the status information, the vehicle controller stops sending stall heating commands to the motor controller and displays a message on the instrument panel indicating that the stall heating function is no longer available.

[0112] After setting the stall heating function enable flag to the disabled state, the motor controller writes the permanently disabled status information of the stall heating function to the non-volatile storage unit. When the vehicle is powered on again, the motor controller reads the permanently disabled status information of the stall heating function from the non-volatile storage unit and directly sets the stall heating function enable flag to the disabled state, without having to compare the count value with the threshold again.

[0113] This application embodiment abandons the response to the stall heating command and disables the stall heating function when the historical count value of stall heating is greater than or equal to the number of available stall heating cycles. This ensures that the stall heating function is permanently disabled after the cumulative execution count reaches the upper limit of the number of available cycles calculated based on the motor insulation life model. This avoids the problem of the motor winding insulation system failing prematurely due to the number of stall heating cycles exceeding the life budget, and fundamentally guarantees the service life of the motor insulation system throughout its entire life cycle.

[0114] In some embodiments of this application, a stall heating control device is provided, which is applied to a vehicle, the vehicle including an energy storage unit and at least one motor.

[0115] Figure 3 Structural block diagrams of stall-heating control devices according to some embodiments of the present disclosure are shown, such as... Figure 3 As shown, the stalled rotor heating control device 300 includes: an acquisition module 302 and a control module 304.

[0116] The acquisition module 302 is used to acquire the historical count value of stall heating and the number of available stall heating cycles when a stall heating command is received. The stall heating command is used to request the motor to perform stall heating operation. The historical count value of stall heating is used to represent the number of valid completions of the stall heating operation performed by the motor. The number of available stall heating cycles is used to represent the maximum number of times the motor can perform stall heating operation. The number of available stall heating cycles is determined based on the total life cycle count of the motor, the thermal aging cycle count, and the thermal management function cycle count. The control module 304 is used to respond to the stall heating command and control the motor to perform stall heating operation to heat the energy storage unit when the stall heating historical count value is less than the number of available stall heating cycles.

[0117] This application embodiment calculates the number of available cycles for stall heating in advance based on the motor insulation life model during the design phase. During actual vehicle use, the motor controller controls the enabling state of the stall heating function based on the comparison between the historical stall heating count and the number of available stall heating cycles. By directly binding the life prediction result with the function enabling condition, active quota management of stall heating cycles is achieved at the functional level. This avoids the problem of premature failure of the motor winding insulation system due to accumulated thermal stress from multiple stall heating cycles, which is caused by protection based solely on real-time heat accumulation or fixed temperature thresholds within a single driving cycle. This reduces the risk of inter-turn short circuits or grounding breakdowns in the motor.

[0118] Please see Figure 4 , Figure 4 Structural block diagrams of electronic devices according to some embodiments of this application are shown. For example... Figure 4As shown, the electronic device 400 may include a processor 402 and a memory 404. The processor 402 is communicatively connected to the memory 404. The memory 404 is used to store a program 406, and the processor 402 is used to execute the program 406, specifically performing the relevant steps described in the embodiment of the stall-heating control method.

[0119] Specifically, program 406 may include program code, which includes computer-executable instructions. Memory 404 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device. Processor 402 may be a central processing unit (CPU), a microcontroller unit (MCU), or an application-specific integrated circuit (ASIC).

[0120] This application also provides a computer-readable storage medium storing at least one executable instruction that, when executed on at least one processor, causes the processor to perform the stall heating control method in any of the above method embodiments.

[0121] This application provides a computer program product, which includes a computer program or instructions. When the computer program or instructions are executed by a processor, they implement the stall heating control method as described in any of the above method embodiments.

[0122] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A stall-rotor heating control method, characterized in that, The method is applied to a vehicle, the vehicle including an energy storage unit and at least one motor, the method comprising: Upon receiving a stall heating command, the system acquires the historical stall heating count and the number of available stall heating cycles. The stall heating command requests the motor to perform a stall heating operation. The historical stall heating count indicates the number of times the motor has completed the stall heating operation. The number of available stall heating cycles indicates the maximum number of times the motor can perform the stall heating operation. The number of available stall heating cycles is determined based on the motor's total lifespan cycles, thermal aging cycles, and thermal management function cycles. If the historical count value of stall heating is less than the number of available stall heating cycles, the motor is controlled to perform the stall heating operation in response to the stall heating command to heat the energy storage unit.

2. The method according to claim 1, characterized in that, The method further includes: Based on the vehicle's overall load condition spectrum, the temperature cycle spectrum of the motor is determined; the temperature cycle spectrum includes the maximum temperature difference of the motor windings in one temperature cycle, and the number of times the temperature cycle occurs; Based on the temperature cycling spectrum, the first target model, and the linear cumulative damage rule, the total number of cycles throughout the lifespan is calculated.

3. The method according to claim 1, characterized in that, The method further includes: The thermal aging life of the motor winding insulation material is determined based on the motor's operating temperature under the target operating conditions and the second target model. The number of thermal aging cycles is calculated based on the thermal aging life and the cycle duration of a single temperature cycle of the motor.

4. The method according to claim 1, characterized in that, The method further includes: The number of cycles of the thermal management function is calculated based on the expected number of operations of at least one thermal management function of the vehicle, the temperature cycle amplitude of the motor winding during the operation of the thermal management function, the first target model and the linear cumulative damage rule.

5. The method according to claim 1, characterized in that, The method further includes: The number of cycles available for stall heating is obtained by subtracting the number of thermal aging cycles from the total life cycle count, and then subtracting the number of thermal management function cycles.

6. The method according to claim 1, characterized in that, The method further includes: After the vehicle is powered on, the stall heating history count value stored in the vehicle's non-volatile memory unit is read; If the read is successful, the stall heating history count value is stored in the flash memory unit of the vehicle's motor controller; In the event of a read failure, the stall heating history count value is initialized to 0, and a corresponding exception flag is generated.

7. The method according to claim 1, characterized in that, The method further includes: After the vehicle is powered on, the status information of the motor controller and the signal detection information of the motor are acquired; If either the status information or the signal detection information is in an abnormal state, the historical count value of the stalled rotor heating is set to a target maximum value; the target maximum value is greater than the number of available stalled rotor heating cycles.

8. The method according to claim 1, characterized in that, The method further includes: If the stall heating operation is successfully executed, the stall heating historical count value is accumulated and updated, and the updated stall heating historical count value is written to the non-volatile storage unit of the vehicle. The stall heating historical count value is configured as a monotonically increasing integer.

9. The method according to claim 8, characterized in that, The step of responding to the stall-rotor heating command and controlling the motor to perform the stall-rotor heating operation to heat the energy storage unit includes: In response to the stall heating command, the motor is controlled to perform the stall heating operation; Obtain the operating power of the motor; If the duration during which the operating power is continuously greater than or equal to the power threshold reaches the target duration, the stall heating operation is determined to have been successfully executed. If the operating power is less than the power threshold within the target duration, the stall heating operation is determined to have failed, the heating command is abandoned, and the stall heating historical count value is not updated.

10. The method according to any one of claims 1 to 9, characterized in that, The method further includes: If the historical count value of stall heating is greater than or equal to the number of available stall heating cycles, the stall heating command is abandoned and the stall heating function of the motor is disabled.

11. A stall-rotor heating control device, characterized in that, The stall heating control device is applied to a vehicle, the vehicle including an energy storage unit and at least one motor, and the stall heating control device includes: The acquisition module is used to acquire the historical count value of stall heating and the number of available stall heating cycles when a stall heating command is received. The stall heating command is used to request the motor to perform stall heating operation. The historical count value of stall heating is used to represent the number of times the motor has completed the stall heating operation. The number of available stall heating cycles is used to represent the maximum number of times the motor can perform the stall heating operation. The number of available stall heating cycles is determined based on the total life cycle count, thermal aging cycle count, and thermal management function cycle count of the motor. The control module is configured to respond to the stall heating command and control the motor to perform the stall heating operation to heat the energy storage unit when the stall heating history count value is less than the number of available stall heating cycles.

12. A vehicle, characterized in that, include: Memory; processor; as well as Computer programs; The computer program is stored in the memory and configured to be executed by the processor to implement the method as described in any one of claims 1-10.

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