Vehicle motor control method and device, vehicle and storage medium

Abstract

The invention relates to a vehicle motor control method and device, a vehicle and a storage medium, and relates to the technical field of vehicle motor control, and the method comprises the steps: responding to a trigger instruction, and increasing the output current upper limit value of a power module in the vehicle; the current upper limit value indicates a current boundary output by the power module, and the trigger instruction indicates to increase the speed of the vehicle; and controlling the vehicle according to the increased upper limit value of the output current. By using the vehicle motor control method provided by the invention, the current output capability of the power module can be improved under the condition of indicating to increase the vehicle speed.

Description

Technical Field

[0001] The present disclosure relates to the technical field of vehicle motor control, and particularly to a vehicle motor control method, device, vehicle and storage medium. Background Art

[0002] Currently, a motor controller is configured on a vehicle. The motor controller is used to control the operation of the motor on the vehicle. A power module is provided in the motor controller, and the current output by the power module acts on the motor, and the motor drives the vehicle to travel.

[0003] In the related art, the current upper limit value of the power module is relatively low, resulting in the current output by the power module being limited within a relatively low current upper limit value, and the short-time acceleration performance of the vehicle is restricted. Summary of the Invention

[0004] To overcome the problems existing in the related art, the present disclosure provides a vehicle motor control method, device, vehicle and storage medium.

[0005] According to the first aspect of the embodiments of the present disclosure, a vehicle motor control method is provided, including:

[0006] In response to a trigger instruction, increasing the upper limit value of the output current of the power module in the vehicle; the current upper limit value indicates the current boundary output by the power module, and the trigger instruction indicates an increase in the speed of the vehicle;

[0007] Controlling the vehicle with the increased upper limit value of the output current.

[0008] Optionally, the increasing the upper limit value of the output current of the power module in the vehicle in response to a trigger instruction includes:

[0009] In response to the trigger instruction, performing at least one of the following to increase the upper limit value of the output current:

[0010] Controlling the upper limit value of the junction temperature of the power module to switch from a first upper limit value of the junction temperature to a second upper limit value of the junction temperature, where the second upper limit value of the junction temperature is greater than the first upper limit value of the junction temperature;

[0011] Reducing the coolant temperature, where the coolant is used to adjust the temperature of the power module;

[0012] Controlling the voltage stress value of the power module to switch from a first voltage stress value to a second voltage stress value, where the second voltage stress value is greater than the first voltage stress value.

[0013] Optionally, the method further includes:

[0014] Based on at least one of the second upper junction temperature value, the reduced coolant temperature, and the second voltage stress value, obtain the increased upper limit value of the output current.

[0015] Optionally, the increasing the upper limit value of the output current of the power module in the vehicle in response to a trigger instruction includes:

[0016] When the vehicle is in the supercharging mode, in response to the trigger instruction, increase the upper limit value of the output current of the power module.

[0017] Optionally, before increasing the upper limit value of the output current of the power module in response to the trigger instruction when the vehicle is in the supercharging mode, the method further includes:

[0018] When the coolant temperature is less than a first preset temperature, control the vehicle to enter the supercharging mode.

[0019] Optionally, the method further includes:

[0020] When the coolant temperature is greater than a second preset temperature, control the vehicle to exit the supercharging mode.

[0021] Optionally, the controlling the vehicle with the increased upper limit value of the output current includes:

[0022] Control the output current of the power module to be within the increased upper limit value of the output current, and control the motor on the vehicle with the current within the increased upper limit value of the output current.

[0023] According to a second aspect of the embodiments of the present disclosure, there is provided a vehicle motor control device, including:

[0024] A response module, configured to increase the upper limit value of the output current of the power module in the vehicle in response to a trigger instruction; the upper limit value of the current indicates the current boundary output by the power module, and the trigger instruction indicates an increase in the speed of the vehicle;

[0025] A control module, configured to control the vehicle with the increased upper limit value of the output current.

[0026] According to a third aspect of the embodiments of the present disclosure, there is provided a vehicle, including:

[0027] A processor;

[0028] A memory for storing processor-executable instructions;

[0029] Wherein, the processor is configured to:

[0030] Execute the steps of the vehicle motor control method provided in the first aspect of the embodiments of the present disclosure.

[0031] According to the fourth aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium on which computer program instructions are stored, and when the program instructions are executed by a processor, the steps of the vehicle motor control method provided in the first aspect of the embodiments of the present disclosure are implemented.

[0032] The technical solutions provided by the embodiments of the present disclosure may include the following beneficial effects:

[0033] When a trigger instruction for increasing the vehicle speed is received, the upper limit value of the current output by the power module can be controlled to increase, so that the current for controlling the vehicle is limited within a larger current boundary. Then, the current for controlling the vehicle can be increased to a larger current, and the acceleration of the vehicle will be greater during the short-time acceleration of the vehicle with a larger current, improving the short-time acceleration performance of the vehicle.

[0034] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure.

[0036] Figure 1 is a flowchart of the steps of a vehicle motor control method shown according to an exemplary embodiment.

[0037] Figure 2 is a control schematic diagram of a power battery, a motor controller and a motor shown according to an exemplary embodiment.

[0038] Figure 3 is a circuit diagram of a power battery, a motor controller and a motor shown according to an exemplary embodiment.

[0039] Figure 4 is a flowchart of a vehicle motor control method shown according to an exemplary embodiment.

[0040] Figure 5 is a schematic diagram of cooling the power module with coolant shown according to an exemplary embodiment.

[0041] Figure 6 is a flowchart of a vehicle motor control method shown according to an exemplary embodiment.

[0042] Figure 7 is a block diagram of a vehicle motor control device shown according to an exemplary embodiment.

[0043] Figure 8 is a block diagram of a vehicle shown according to an exemplary embodiment.

[0044] Figure 9 is a block diagram of a chip system shown according to an exemplary embodiment. Detailed implementation manners

[0045] Here, the exemplary embodiments will be described in detail, and examples thereof are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present disclosure. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0046] It should be noted that all actions of obtaining signals, information, or data in the present disclosure are carried out on the premise of complying with the corresponding data protection regulations and policies of the country where it is located and obtaining authorization from the owner of the corresponding device.

[0047] Figure 1 is a step flowchart of a vehicle motor control method shown according to an exemplary embodiment, as Figure 1 shown, including the following steps.

[0048] In step S10, in response to a trigger instruction, the upper limit value of the output current of the power module in the vehicle is increased.

[0049] The trigger instruction is used to indicate an increase in vehicle speed, for example, to indicate that the vehicle increases its speed within a preset time period. The trigger instruction can be a mechanical button on the vehicle or a trigger button on a screen such as the vehicle's central control screen. After the user presses the mechanical button or clicks the trigger button on the central control screen, the vehicle will increase its speed in a short time.

[0050] The power module is a power device that performs current conversion in the motor controller. Please refer to Figure 2 shown, a power battery, a motor controller, and a motor are configured on the vehicle. The power battery provides electrical energy for the motor controller, and the motor controller controls the motor to convert the electrical energy into mechanical energy, thereby driving the driving wheels of the vehicle to rotate to drive the vehicle to travel. Of course, the motor controller can also convert the excess mechanical energy generated by the motor into electrical energy and feedback the electrical energy to the power battery to charge the power battery.

[0051] Among them, the power battery provides electrical energy for the vehicle, but the voltage provided by the power battery is direct current and its voltage cannot be directly used by the motor. Please refer to Figure 3As shown, the power battery may include a battery pack Vdc, and the battery pack includes a first battery module and a second battery module.

[0052] Among them, the motor controller is used to convert the DC voltage of the battery into an AC voltage by inversion, and then deliver the AC voltage to the motor to supply electrical energy to the motor. Figure 3 The output current ia of the motor controller on lines a, b, and c is respectively transmitted to the three phases of the motor; the motor controller can also convert the AC voltage generated by the motor into a DC voltage, and then deliver the DC voltage to the power battery to charge the power battery. The motor controller contains at least one power module, and each power module includes at least one upper bridge arm and at least one lower bridge arm. Please refer to Figure 3 As shown, the motor controller may include a power module, and the power module includes three upper bridge arms S1, S3, S5 and three lower bridge arms S2, S4, S6; the motor controller may also include three power modules, and each power module contains one upper bridge arm and one lower bridge arm. The power module realizes the function of converting the DC voltage of the battery into an AC voltage by inversion, and then delivering the AC voltage to the motor to supply electrical energy to the motor; it also realizes the function of converting the AC voltage generated by the motor into a DC voltage, and then delivering the DC voltage to the power battery. Please refer to Figure 3 As shown, by controlling the on and off of multiple bridge arms, the DC voltage generated by the power battery is converted into an AC voltage, or the AC voltage generated by the motor is converted into a DC voltage.

[0053] The current upper limit value is the current boundary output by the power module, and the current output by the power module is used to supply the motor.

[0054] When the trigger instruction is triggered, it indicates that the vehicle speed needs to be increased in a short time. Therefore, the output current upper limit value of the power module can be controlled to increase, and the boundary of the output current of the power module is limited to be larger. In this way, when the trigger instruction is triggered, the power module can be controlled to output a larger current ia to achieve the short-time acceleration of the vehicle.

[0055] In step S20, the vehicle is controlled with the increased output current upper limit value.

[0056] Optionally, the current output by the power module can be controlled to be limited within the increased output current upper limit value, and the motor on the vehicle is controlled with the current within the increased output current upper limit value.

[0057] For example, after obtaining the increased output current upper limit value, the increased output current upper limit value can be used as the current boundary output by the power module, and the current output by the power module to the motor is controlled not to exceed the increased output current upper limit value. In this way, the motor will use the current not exceeding the increased output current upper limit value to drive the vehicle to travel.

[0058] It is understandable that the greater the current output by the power module to the motor, the greater the driving torque of the motor to control the driving wheel, and then the greater the driving acceleration of the vehicle.

[0059] Through the above technical solution, when a trigger instruction to increase the vehicle speed is received, the upper limit value of the current output by the power module can be controlled to increase, so that the current for controlling the vehicle is limited within a larger current boundary. Then, the current for controlling the vehicle can be increased to a larger current, and the acceleration of the vehicle will be greater during the short-time acceleration of the vehicle with a larger current, improving the short-time acceleration performance of the vehicle.

[0060] Figure 4 This is an exemplary embodiment related to the above step S10, which is used to interpret an exemplary solution for obtaining an increased upper limit value of the output current by using at least one of the second upper limit value of the junction temperature, the reduced coolant temperature, and the second voltage stress value, and it includes the following steps:

[0061] In step S11, in response to the trigger instruction, at least one of the following solutions A1, A2, and A3 is executed to increase the upper limit value of the output current.

[0062] Solution A1, control the upper limit value of the junction temperature of the power module to switch from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature.

[0063] A single bridge arm in the power module includes multiple power chips, and the multiple power chips are connected in parallel. When the power chips are working, current will flow through the bridge arm in the power chips, causing the power chips corresponding to the bridge arm to generate heat. The material of the power chips is a semiconductor material, and semiconductors have a temperature upper limit. Within the temperature upper limit, the power chips will not be damaged due to overheating; the encapsulation material of the power module also has a temperature upper limit. Therefore, the upper limit value of the junction temperature of the power module depends on the temperature upper limit value of the power chips inside the power module and the temperature upper limit value of the encapsulation material outside the power module. In this context, the junction temperature value of the power module is the highest temperature of the power module. The upper limit value of the junction temperature of the power module is the boundary of the highest temperature of the power module, which is used to limit the highest temperature of the power module below the upper limit value of the junction temperature.

[0064] Among them, there is the following relationship between the upper limit value of the junction temperature of the power module, the coolant temperature, and the electrical energy of power loss:

[0065] Tjmax = Tcoolant + Ploss * Rth (1)

[0066] In Equation (1), Tjmax is the upper limit of the junction temperature of the power module. This upper limit of the junction temperature is the pre-configured upper limit of the junction temperature of the power module, and this upper limit of the junction temperature is less than or equal to the maximum temperature that the power module can actually withstand. For example, if the maximum temperature that the power module can actually withstand is 200 °C, then an upper limit of the junction temperature below 200 °C can be pre-configured for the power module; Tcoolant is the coolant temperature; Ploss is the electrical energy dissipated by the power module, which can also be understood as the electrical energy dissipated by the upper limit of the output current of the power module, and its unit is KW; Rth is the thermal resistance of the power module, and its unit is °C / KW.

[0067] It can be seen from Equation (1) that the upper limit of the junction temperature of the power module is equal to the coolant temperature plus the product of the electrical energy dissipated by the power module and the thermal resistance of the power module. Please refer to Figure 5 As shown, when the power chip in the power module releases heat, there will be a thermal resistance during the process of transferring the released heat to the coolant. This thermal resistance is the thermal resistance value brought by the ceramic insulation liner, the heat dissipation substrate, and the related solder plates, etc., resulting in a change in the coolant temperature. During this process, under the same loss, the thermal resistance is used to characterize the ease of transferring the heat generated by the power module to the coolant. The larger the thermal resistance, the less conducive it is to the heat dissipation of the power module; the smaller the thermal resistance, the smoother the heat conduction, the better the heat dissipation effect, and the easier it is for the heat of the power module to be transferred to the coolant. Then, the product of the electrical energy dissipated by the power module and the thermal resistance of the power module represents the temperature brought by the thermal resistance in the physical link of transferring the heat generated by the power module to the coolant. The junction temperature value of the power module is mainly composed of the temperature on the thermal resistance and the coolant temperature. Therefore, the temperature brought by the thermal resistance can be superimposed on the basis of the coolant temperature to obtain the junction temperature value of the power module.

[0068] It can be understood that in Equation (1), if the electrical energy dissipated by the power module is generated under the condition of the upper limit of the output current of the power module, and this electrical energy dissipated by the power module is the loss brought by the output current being the upper limit of the current, then the upper limit of the junction temperature of the power module is obtained through Equation (1); if the electrical energy dissipated by the power module is generated under the condition of the output current of the power module, then the junction temperature value of the power module is obtained through Equation (1).

[0069] Among them, in Equation (1), the electrical energy dissipated by the power module is calculated through the following Equation (2):

[0070] Ploss≈Psw+Pcon(2)

[0071] In Equation (2), Ploss is the electrical energy dissipated by the power module, Psw is the switching loss value of the power module, which is the electrical energy dissipated when the power module is turned on and off, and Pcon is the conduction loss value of the power module, which is the electrical energy dissipated when the power module is conducting.

[0072] As can be seen from the above formula (2), most of the electrical energy lost by the power module comes from the switching loss value and conduction loss value of the power module. The switching loss of the power module includes the turn-on loss value and turn-off loss value. The turn-on loss value refers to the situation where when the MOS transistor in the bridge arm of the power module turns on, the voltage does not immediately drop to 0 and the current does not immediately rise to the load current. There is an overlapping region between the two, resulting in losses. The turn-off loss value is similar to the turn-on loss value and refers to the loss generated in the overlapping region of voltage and current when the MOS transistor turns off. The conduction loss value of the power module refers to the loss caused by the voltage drop when the current passes through a certain resistance inside the MOS transistor after it turns on. This conduction loss value is related to the resistance value of the resistance. The larger the resistance value, the larger the conduction loss value. Among them, the MOS transistor can be a SiC MOS transistor.

[0073] Among them, in formula (2), the switching loss value can be approximately calculated through the following formula (3):

[0074] Psw ≈ Udc*Idc*(Ton+Toff) / 2*fsw(3)

[0075] In formula (3), Psw is the switching loss value of the power module; Udc is the high-voltage battery voltage. Please refer to Figure 3 As shown, the high-voltage battery voltage refers to the voltage Vdc of the power battery on the vehicle; Idc is the upper limit value of the output current; Ton is the turn-on time, which is the duration consumed for the power module to turn on; Toff is the turn-off time, which is the duration consumed for the power module to turn off; fsw is the switching frequency.

[0076] As can be seen from the above formula (3), the switching loss value of the power module can be obtained based on the high-voltage battery voltage, the upper limit value of the output current, the turn-on time, and the turn-off time. For example, the average value of the turn-on time and turn-off time can be calculated first, and then the product of the average value, the high-voltage battery voltage, and the upper limit value of the output current can be used as the switching loss value of the power module.

[0077] Among them, in formula (2), the conduction loss value can be obtained through the following formula (4):

[0078] Pcon=Idc 2 *Rdson*D (4)

[0079] In formula (4), Pcon is the conduction loss value of the power module; Idc is the upper limit value of the output current; Rdson is the on-resistance between the drain and source of the power chip; D is the duty cycle corresponding to conduction.

[0080] As can be seen from the above formula (4), the conduction loss value of the power module can be obtained based on the upper limit value of the output current, the on-resistance of the drain-source of the power chip, and the duty cycle during conduction.

[0081] After substituting the above formulas (3) and (4) into formula (2), the following formula (5) can be obtained:

[0082] Ploss≈Udc*Idc*(Ton+Toff) / 2*fsw+Idc 2 *Rdson*D(5)

[0083] Substituting the above formula (5) into the above formula (1) again, the following formula (6) can be obtained:

[0084] Tjmax≈Tcoolant+[Udc*Idc*(Ton+Toff) / 2*fsw+Idc 2 *Rdson*D]*Rth(6)

[0085] In formula (6), Tjmax is the upper limit value of the junction temperature of the power module; Tcoolant is the coolant temperature; Udc is the high-voltage battery voltage; Idc is the upper limit value of the output current; Ton is the turn-on time; Toff is the turn-off time; Rdson is the on-resistance of the drain-source of the power chip; D is the duty cycle corresponding to conduction.

[0086] As can be seen from the above formula (6), the upper limit value of the junction temperature of the power module is positively correlated with the upper limit value of the output current. Therefore, the upper limit value of the junction temperature of the power module can be controlled to increase from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature, thereby increasing the upper limit value of the output current of the power module.

[0087] Long-term operating condition Short-term acceleration operating condition Upper limit value of the junction temperature of the power module 175℃ 185℃～200℃

[0088] Table 1

[0089] Exemplarily, for increasing the upper limit value of the junction temperature, as shown in Table 1, currently in a vehicle with a power battery of 800V, the upper limit value of the junction temperature of the power chip in the power module under long-term working conditions is 175°C, while the upper limit value of the junction temperature under short-term acceleration working conditions can reach 185°C - 200°C. In this context, taking the first upper limit value of the junction temperature as 175°C and the second upper limit value of the junction temperature as 185°C as an example, the present disclosure can, in response to a trigger command, determine that when it is necessary to increase the vehicle speed in a short time, control the upper limit value of the junction temperature of the power module to increase from the first upper limit value of the junction temperature of 175°C to the second upper limit value of the junction temperature of 185°C, thereby increasing the upper limit value of the output current of the power module.

[0090] It can be understood that when controlling the upper limit value of the junction temperature of the power chip, the actual released upper limit value of the junction temperature can be obtained by multiplying the upper limit value of the junction temperature described in Table 1 by a coefficient K, so as to limit the actual released junction temperature value of the power chip within the upper limit value of the junction temperature, where K is less than 1. For example, taking K as 0.88, although the power module can withstand an upper limit value of the junction temperature of 200 °C under short-time acceleration conditions, the upper limit value of the junction temperature can be multiplied by the coefficient 0.88 for the upper limit value of the junction temperature of 200 °C, and the finally released upper limit value of the junction temperature is 176 °C, without exceeding the upper limit value of the junction temperature of 200 °C.

[0091] Solution A2: Lower the coolant temperature. The coolant is used to regulate the temperature of the power module.

[0092] The power module includes a power chip and a ceramic insulating substrate, a heat dissipation substrate, and related solders arranged below the power chip. The heat dissipated by the power chip is transferred to the coolant through the ceramic insulating substrate, the heat dissipation substrate, and related solders, etc., to achieve cooling of the power chip. Cooling the power chip means achieving cooling of the power module. In this context, the coolant temperature is the coolant temperature at the current time, and it can also be understood as the coolant temperature brought about after the power chip / power module dissipates heat to the coolant.

[0093] It can be seen from the above formula (6) that the coolant temperature is negatively correlated with the upper limit value of the output current. Therefore, the coolant temperature can be controlled to decrease to increase the upper limit value of the output current of the power module.

[0094] Regarding lowering the coolant temperature, the coolant temperature is the current temperature of the coolant after cooling the power module. To increase the maximum output current, the radiator on the vehicle can be controlled to cool the coolant, so that the coolant temperature decreases, thereby increasing the upper limit value of the output current of the power module. It can be understood that the lowered coolant temperature is greater than or equal to the ambient temperature of the vehicle, which means that the coolant temperature cannot be infinitely decreased, but is bounded by the ambient temperature of the vehicle, and the lowered coolant temperature is controlled to be greater than or equal to the ambient temperature.

[0095] Solution A3: Control the voltage stress value of the power module to switch from a first voltage stress value to a second voltage stress value.

[0096] The voltage stress value is the maximum voltage stress value that the power module can reach under the current operating conditions. The voltage stress value of the power module is positively correlated with the upper limit value of the output current of the power module. The larger the upper limit value of the output current, the larger the corresponding voltage stress value. Therefore, the voltage stress value can be determined first. To determine the voltage stress value of the power module, it is necessary to switch from the first voltage stress value to the second voltage stress value, and the second voltage stress value is greater than the first voltage stress value. Then, control the upper limit value of the output current within the increased current upper limit value, so that the voltage stress value of the power module is within the second voltage stress value.

[0097] Long-term operating condition Short-term acceleration operating condition Voltage stress value of the power module 1200V 1350 / 1400V

[0098] Table 2

[0099] For the voltage stress value, as shown in Table 2, the voltage stress value of the power module is 1200V under long-term operating conditions, and the voltage stress value can reach 1350V or 1400V under short-term acceleration operating conditions. In this context, taking the first voltage stress value as 1200V and the second voltage stress value as 1350V or 1400V as an example, in response to a trigger command, when it is determined that the vehicle speed needs to be increased in a short time, control the voltage stress value of the power module to increase from the first voltage stress value of 1200V to the second voltage stress value of 1350V or 1400V, thereby increasing the upper limit value of the output current of the power module.

[0100] It can be understood that when using the voltage stress value of the power module, the actual voltage stress value can be obtained by multiplying the voltage stress value shown in Table 2 by the coefficient M, so as to limit the voltage stress value actually generated by the power module within the maximum voltage stress value corresponding to different operating conditions, and M is less than 1. For example, taking M as 0.88, although the power module can withstand a voltage stress value of 1400V under short-term acceleration operating conditions, the coefficient 0.88 can be multiplied by the voltage stress value of 1400V to obtain the final second voltage stress value that can be withstood is 1232V, without exceeding 1400V.

[0101] In step S12, the increased upper limit value of the output current is obtained according to at least one of the second upper limit value of the junction temperature, the reduced coolant temperature and the second voltage stress value.

[0102] Obtaining the increased upper limit value of the output current based on at least one of the second upper limit value of the junction temperature, the reduced coolant temperature, and the second voltage stress value includes: obtaining a first upper limit value of the current based on the second upper limit value of the junction temperature and / or the reduced coolant temperature; obtaining a second upper limit value of the current based on the second voltage stress value or the voltage stress value; and taking the minimum value of the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current, which includes the following multiple combination schemes, and the following multiple combination schemes can be selected according to the actual situation to obtain the increased upper limit value of the output current.

[0103] Scheme B1: Obtaining the increased upper limit value of the output current based on the second upper limit value of the junction temperature.

[0104] In the case where the coolant temperature cannot continue to decrease and the voltage stress value cannot continue to increase, the upper limit value of the junction temperature of the power module can be controlled to increase from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature, and the increased upper limit value of the output current can be obtained based on the second upper limit value of the junction temperature, the coolant temperature, and the voltage stress value.

[0105] For example, as shown in the above formula (6), the first upper limit value of the current is obtained based on the second upper limit value of the junction temperature and the coolant temperature; then the second upper limit value of the current is obtained based on the voltage stress value, and then the minimum value is selected from the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current.

[0106] Scheme B2: Obtaining the increased upper limit value of the output current based on the reduced coolant temperature.

[0107] In the case where the upper limit value of the junction temperature cannot continue to increase and the voltage stress value cannot continue to increase, the coolant temperature can be controlled to decrease to the reduced coolant temperature, and the increased upper limit value of the output current can be obtained based on the reduced coolant temperature, the upper limit value of the junction temperature, and the voltage stress value.

[0108] For example, as shown in the above formula (6), the first upper limit value of the current is obtained based on the upper limit value of the junction temperature and the reduced coolant temperature; then the second upper limit value of the current is obtained based on the voltage stress value, and then the minimum value is selected from the first upper limit value of the current and the second upper limit value of the current as the finally increased upper limit value of the output current.

[0109] Scheme B3: Obtaining the increased upper limit value of the output current based on the second voltage stress value.

[0110] When the upper limit value of the junction temperature cannot be further increased and the coolant temperature cannot be further decreased (for example, decreased to the ambient temperature), the voltage stress value can be controlled to increase from the first voltage stress value to the second voltage stress value, and the increased upper limit value of the output current can be obtained based on the coolant temperature, the upper limit value of the junction temperature, and the second voltage stress value.

[0111] For example, there is a corresponding relationship between each voltage stress value and an upper limit value of the current. After determining the second voltage stress value, the increased upper limit value of the output current corresponding to the second voltage stress value can be obtained according to this corresponding relationship.

[0112] The first upper limit value of the current can be obtained based on the upper limit value of the junction temperature and the coolant temperature; then the second upper limit value of the current can be obtained according to the second voltage stress value, and the minimum value can be selected from the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current.

[0113] Solution B4: The increased upper limit value of the output current is obtained according to the second upper limit value of the junction temperature and the decreased coolant temperature.

[0114] When the voltage stress value cannot be further increased, the upper limit value of the junction temperature can be controlled to increase from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature, and the coolant temperature is controlled to decrease, and the increased upper limit value of the output current is obtained according to the second upper limit value of the junction temperature and the decreased coolant temperature.

[0115] For example, the first upper limit value of the current can be obtained according to the second upper limit value of the junction temperature and the decreased coolant temperature; then the second upper limit value of the current can be obtained according to the voltage stress value, and the minimum value can be selected from the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current.

[0116] Solution B5: The increased upper limit value of the output current is obtained according to the second upper limit value of the junction temperature and the second voltage stress value.

[0117] When the coolant temperature cannot be further decreased, the upper limit value of the junction temperature can be controlled to increase from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature, and the voltage stress value can be controlled to increase from the first voltage stress value to the second voltage stress value, and the increased upper limit value of the output current is obtained according to the second upper limit value of the junction temperature and the second voltage stress value.

[0118] For example, the first upper limit value of the current can be obtained according to the second upper limit value of the junction temperature and the coolant temperature; then the second upper limit value of the current can be obtained according to the second voltage stress value, and the minimum value can be selected from the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current.

[0119] Referring to Table 1, the upper limit value of the junction temperature of the power module can be increased from the first upper limit value of 175 °C to the second upper limit value of 185 °C, and referring to Table 2, the voltage stress value of the power module can be increased from the first voltage stress value of 1200 V to the second voltage stress value of 1350 V or 1400 V.

[0120] For Solution B6, based on the reduced coolant temperature and the second voltage stress value, the increased upper limit value of the output current is obtained.

[0121] When the upper limit value of the junction temperature cannot be increased, the coolant temperature can be controlled to decrease, and the voltage stress value can be controlled to increase from the first voltage stress value to the second voltage stress value, and based on the reduced coolant temperature and the second voltage stress value, the increased upper limit value of the output current is obtained.

[0122] For example, based on the upper limit value of the junction temperature and the reduced coolant temperature, the first upper limit value of the current can be obtained; then based on the second voltage stress value, the second upper limit value of the current can be obtained, and then the minimum value is selected from the first upper limit value of the current and the second upper limit value of the current as the increased upper limit value of the output current.

[0123] For Solution B7, based on the second upper limit value of the junction temperature, the reduced coolant temperature and the second voltage stress value, the increased upper limit value of the output current is obtained.

[0124] When the upper limit value of the junction temperature can be increased, the coolant temperature can be decreased, and the voltage stress value can be increased, the upper limit value of the junction temperature can be controlled to increase from the first upper limit value of the junction temperature to the second upper limit value of the junction temperature, the coolant temperature can be controlled to decrease, and the voltage stress value can be controlled to increase from the first voltage stress value to the second voltage stress value, and based on the second upper limit value of the junction temperature, the reduced coolant temperature and the second voltage stress value, the increased upper limit value of the output current is obtained.

[0125] For example, based on the second upper limit value of the junction temperature and the reduced coolant temperature, the first upper limit value of the current can be obtained; based on the second voltage stress value, the second upper limit value of the current can be obtained; the minimum value of the first upper limit value of the current and the second upper limit value of the current is used as the increased upper limit value of the output current.

[0126] In the above solutions, the electrical energy lost by the power module can be obtained based on the second junction temperature upper limit value and / or the reduced coolant temperature; the first current upper limit value can be obtained based on the electrical energy lost by the power module. For example, in Solution B1, the electrical energy lost by the power module can be obtained based on the second junction temperature upper limit value and the coolant temperature; then, based on the electrical energy lost by the power module, the high-voltage battery voltage, the turn-on time, the turn-off time, the drain-source on-resistance of the power chip, and the duty cycle, the output current upper limit value can be obtained. For example, in Solution B2, the electrical energy lost by the power module can be obtained based on the junction temperature upper limit value and the reduced coolant temperature; then, based on the electrical energy lost by the power module, the high-voltage battery voltage, the turn-on time, the turn-off time, the drain-source on-resistance of the power chip, and the duty cycle, the output current upper limit value can be obtained. For example, in Solution B4, the electrical energy lost by the power module can be obtained based on the second junction temperature upper limit value and the reduced coolant temperature; then, based on the electrical energy lost by the power module, the high-voltage battery voltage, the turn-on time, the turn-off time, the drain-source on-resistance of the power chip, and the duty cycle, the output current upper limit value can be obtained.

[0127] In the above solutions, the second current upper limit value can be obtained based on the second voltage stress value or the voltage stress value. For example, in Solutions B1, B2, and B4, the voltage stress value is used to obtain the second current upper limit value, while in the remaining solutions, the second voltage stress value is used to obtain the second current upper limit value.

[0128] It can be understood that the voltage stress value of the power module can be any one of 1200V, 1350V, and 1400V. It does not need to respond to the trigger instruction to control the voltage stress value of the power module to increase from 1200V to the second voltage stress value of 1350V or 1400V. The voltage stress value of the power module itself has the ability to have any one of the voltage stress values of 1200V, 1350V, and 1400V, and the maximum output current of the power module can be directly calculated based on the second voltage stress value. Therefore, in the above 7 solutions, controlling the voltage stress value to increase to the second voltage stress value actually participates in the calculation of the increased output current upper limit value with a larger second voltage stress value.

[0129] Through the above technical solutions, the output current limit value of the power module can be increased by at least one of increasing the junction temperature upper limit value of the power module, reducing the coolant temperature, and increasing the voltage stress value, thereby improving the current output ability of the power module. When the vehicle has a faster acceleration requirement, a larger current can be provided to the vehicle to meet the faster acceleration requirement.

[0130] Moreover, when selecting the minimum value from the first current upper limit value and the second current upper limit value as the output current upper limit value (the increased output current upper limit value) of the power module, the voltage stress value obtained based on this output current upper limit value will not exceed the limit voltage stress value, and the junction temperature upper limit value obtained based on this output current upper limit value will also not exceed the limit junction temperature upper limit value, thus ensuring the normal operation of the power module on the vehicle.

[0131] Figure 6 is an exemplary embodiment related to the above step S10, which is used to interpret an exemplary solution for controlling the increase of the output current upper limit value of the power module, including:

[0132] In step S13, when the coolant temperature is less than the first preset temperature, control the vehicle to enter the overboost mode.

[0133] The overboost mode can also be referred to as a short-time acceleration mode. In the overboost mode, the vehicle can achieve rapid supercharging within a short time, and then achieve short-time acceleration.

[0134] When the coolant temperature is less than the first preset temperature, it indicates that the coolant temperature is relatively low at this time. Even if the temperature dissipated by the power module of the vehicle is relatively high, the coolant can still cool and dissipate heat for it. Therefore, the vehicle can enter the overboost mode so as to use a lower coolant temperature to dissipate heat from the power module subsequently.

[0135] Optionally, when the coolant temperature is greater than the second preset temperature, control the vehicle to exit the overboost mode. The second preset temperature is greater than or equal to the first preset temperature.

[0136] When the coolant temperature is greater than the second preset temperature, it indicates that the coolant temperature is relatively high at this time. The relatively high coolant temperature cannot dissipate heat from the power module well. If the vehicle is in the overboost mode, it will cause the temperature of the power module to rise further, and there is a high possibility that the temperature of the power module is relatively high and the coolant cannot quickly cool the power module, resulting in damage to the power module due to excessive temperature. Therefore, when the coolant temperature is greater than the second preset temperature, the vehicle can be controlled to exit the overboost mode or be in a non-overboost mode.

[0137] Optionally, controlling the vehicle to enter the overboost mode includes: controlling the motor controller on the vehicle to enter the overboost mode; controlling the vehicle to exit the overboost mode includes: controlling the motor controller on the vehicle to exit the overboost mode.

[0138] In step S14, when the vehicle is in the overboost mode, in response to the trigger instruction, increase the output current upper limit value of the power module.

[0139] When the vehicle is in the overboost mode, it indicates that the vehicle has the ability to respond to the trigger command, that is, the vehicle has the ability to meet the user's short-term acceleration demand. At this time, if the trigger command is triggered, it means that the user has a short-term acceleration demand. Therefore, the upper limit value of the output current of the power module can be controlled to increase, so as to improve the current output ability of the power module.

[0140] Optionally, when the vehicle is in the non-overboost mode, the trigger command may not be responded to.

[0141] In the related art, when designing the upper limit value of the junction temperature of the power module, the upper limit value of the junction temperature under long-term working conditions is usually 175°C to obtain the upper limit value of the current output. However, the upper limit value of the junction temperature of the power module itself can reach 180°C or even 200°C under short-term working conditions. Therefore, the upper limit value of the current output obtained according to the junction temperature of 175°C is small, and the current output ability of the power module is limited. Moreover, when designing the voltage stress value of the power module, the voltage stress value under long-term working conditions is usually 1200V to obtain the upper limit value of the current output. However, the voltage stress value of the power module itself can reach 1350V or 1400V under short-term working conditions. Therefore, the upper limit value of the current output obtained according to the voltage stress value of 1200V is also small, and the current output ability of the power module is limited.

[0142] In the present disclosure, the overboost mode is a short-term acceleration working condition, and its single acceleration cycle is usually about 5S. Therefore, after the vehicle enters the overboost mode, the upper limit value of the junction temperature of the power module can be increased to 180°C or even 200°C, and the voltage stress value of the power module can be increased to 1350V or 1400V, and the upper limit value of the current output is increased accordingly. On the one hand, it ensures the current output ability in the overboost mode, so that the vehicle can complete the short-term acceleration in the overboost mode with a greater driving acceleration. On the other hand, since the overboost mode itself is a short-term acceleration working condition, the increase in the voltage stress value and the upper limit value of the junction temperature under short-term working conditions will not cause a great impact on the power module, ensuring the use safety of the power module.

[0143] Through the above technical solution, when the coolant temperature is less than the first preset temperature, the vehicle can be controlled to enter the overboost mode, and then in the overboost mode, the trigger command of the user is responded to, and the upper limit value of the output current of the power module is controlled to increase. During this process, since the coolant temperature is low, the low coolant temperature can quickly cool the power module after entering the overboost mode, avoiding damage to the power module due to excessive temperature.

[0144] Figure 7 is a block diagram of a vehicle motor control device shown according to an exemplary embodiment. Refer to Figure 7 , the vehicle motor control device 700 includes a response module 710 and a control module 720.

[0145] A response module 710, configured to increase the upper limit value of the output current of a power module in a vehicle in response to a trigger instruction; the current upper limit value indicates the current boundary output by the power module, and the trigger instruction indicates an increase in the speed of the vehicle.

[0146] A control module 720, configured to control the vehicle with the increased upper limit value of the output current.

[0147] Optionally, the response module 710 is further configured to, in response to the trigger instruction, perform at least one of the following to increase the upper limit value of the output current:

[0148] Control the upper limit value of the junction temperature of the power module to switch from a first upper limit value of the junction temperature to a second upper limit value of the junction temperature, where the second upper limit value of the junction temperature is greater than the first upper limit value of the junction temperature;

[0149] Lower the coolant temperature, where the coolant is used to regulate the temperature of the power module;

[0150] Control the voltage stress value of the power module to switch from a first voltage stress value to a second voltage stress value, where the second voltage stress value is greater than the first voltage stress value.

[0151] Optionally, the vehicle motor control device 700 further includes:

[0152] A calculation module, configured to obtain the increased upper limit value of the output current based on at least one of the second upper limit value of the junction temperature, the reduced coolant temperature, and the second voltage stress value.

[0153] Optionally, the response module 710 is further configured to, when the vehicle is in a supercharging mode, increase the upper limit value of the output current of the power module in response to the trigger instruction.

[0154] Optionally, the vehicle motor control device 700 further includes:

[0155] An entry module, configured to control the vehicle to enter the supercharging mode when the coolant temperature is less than a first preset temperature.

[0156] Optionally, the vehicle motor control device 700 further includes:

[0157] An exit module, configured to control the vehicle to exit the supercharging mode when the coolant temperature is greater than a second preset temperature.

[0158] Optionally, the control module 720 is further configured to control the output current of the power module to be within the increased upper limit value of the output current, and control the motor on the vehicle with the current within the increased upper limit value of the output current.

[0159] Regarding the device in the above embodiments, the specific manners in which each module performs operations have been described in detail in the embodiments related to the method, and will not be elaborated herein.

[0160] The present disclosure also provides a computer-readable storage medium, on which computer program instructions are stored. When the program instructions are executed by a processor, the steps of the vehicle motor control method provided by the present disclosure are implemented.

[0161] Figure 8 is a block diagram of a vehicle 800 shown according to an exemplary embodiment. For example, the vehicle 800 may be a hybrid vehicle, or a non-hybrid vehicle, an electric vehicle, a fuel cell vehicle, or other types of vehicles. The vehicle 800 may be an autonomous vehicle, a semi-autonomous vehicle, or a non-autonomous vehicle.

[0162] Referring to Figure 8 , the vehicle 800 may include various subsystems. For example, the infotainment system 810, the perception system 820, the decision control system 830, the drive system 840, and the computing platform 850. Among them, the vehicle 800 may further include more or fewer subsystems, and each subsystem may include multiple components. In addition, each subsystem and each component of the vehicle 800 may be interconnected in a wired or wireless manner.

[0163] In some embodiments, the infotainment system 810 may include a communication system, an entertainment system, and a navigation system, etc.

[0164] The perception system 820 may include several sensors for sensing information about the environment around the vehicle 800. For example, the perception system 820 may include a global positioning system (the global positioning system may be a GPS system, or a Beidou system, or other positioning systems), an inertial measurement unit (IMU), lidar, millimeter-wave radar, ultrasonic radar, and a camera device.

[0165] The decision control system 830 may include a computing system, a vehicle controller, a steering system, an accelerator, and a braking system.

[0166] The drive system 840 may include components that provide power movement for the vehicle 800. In one embodiment, the drive system 840 may include an engine, an energy source, a transmission system, and wheels. The engine may be one or a combination of an internal combustion engine, an electric motor, and an air compression engine. The engine can convert the energy provided by the energy source into mechanical energy.

[0167] Some or all functions of vehicle 800 are controlled by computing platform 850. The computing platform 850 may include at least one processor 851 and a memory 852, and the processor 851 may execute instructions 853 stored in the memory 852.

[0168] The processor 851 may be any conventional processor, such as a commercially available CPU. The processor may also include, for example, a Graphic Process Unit (GPU), a Field Programmable Gate Array (FPGA), a System on Chip (SOC), an Application Specific Integrated Circuit (ASIC), or a combination thereof.

[0169] The memory 852 may 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 memory, flash memory, a magnetic disk, or an optical disk.

[0170] In addition to the instructions 853, the memory 852 may also store data, such as road maps, route information, data such as the position, direction, and speed of the vehicle. The data stored in the memory 852 may be used by the computing platform 850.

[0171] In an embodiment of the present disclosure, the processor 851 may execute the instructions 853 to complete all or part of the steps of the above-described vehicle motor control method.

[0172] In another exemplary embodiment, a computer program product is also provided. The computer program product includes a computer program that can be executed by a programmable device. The computer program has a code portion for executing the above-described vehicle motor control method when executed by the programmable device. For example, parameters such as the upper limit value of the second junction temperature and the second voltage stress value of the power module may be set in the computer program product.

[0173] Some embodiments of the present disclosure also provide a chip system, such as Figure 9As shown, the chip system includes at least one processor 901 and at least one interface circuit 902. The processor 901 and the interface circuit 902 can be interconnected by a line. For example, the interface circuit 902 can be used to receive signals from other devices (such as the memory of an electronic device). Also for example, the interface circuit 902 can be used to send signals to other devices (such as the processor 901). Exemplarily, the interface circuit 902 can read the instructions stored in the memory and send the instructions to the processor 901. When the instructions are executed by the processor 901, the vehicle motor control device can be made to execute each step in the above embodiments. Of course, the chip system can also include other discrete devices, and some embodiments of the present disclosure do not specifically limit this.

[0174] In some embodiments of the present disclosure, the interface circuit 902 can obtain data, program instructions, and / or information, etc. in the internal storage area of the chip system; or can also obtain data, program instructions, and / or information, etc. from outside the chip system.

[0175] Optionally, the chip system can also include a memory, and the memory is used to store necessary computer programs and data.

[0176] Those skilled in the art can also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of the two. Whether such a function is implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can use various methods to implement the described function for each specific application, but such an implementation should not be construed as exceeding the scope protected by the embodiments of the present application.

Claims

1. A vehicle motor control method, characterized in that: include: In response to a trigger instruction, increasing an upper limit value of an output current of a power module in a vehicle; The current upper limit value indicates the current boundary of the power module output, and the trigger instruction indicates to increase the speed of the vehicle; The vehicle is controlled with the increased output current upper limit value.

2. The method according to claim 1, characterized in that In response to the trigger instruction, increasing the upper limit of the output current of the power module in the vehicle includes: In response to the trigger instruction, at least one of the following is performed to increase the output current upper limit value: Controlling a junction temperature upper limit value of the power module to switch from a first junction temperature upper limit value to a second junction temperature upper limit value, wherein the second junction temperature upper limit value is greater than the first junction temperature upper limit value; Lowering the temperature of the coolant, where the coolant is used to adjust the temperature of the power module; The voltage stress value of the power module is controlled to switch from a first voltage stress value to a second voltage stress value, wherein the second voltage stress value is greater than the first voltage stress value.

3. The method according to claim 2, characterized in that The method further comprises: The increased output current upper limit value is obtained according to at least one of the second junction temperature upper limit value, the reduced coolant temperature and the second voltage stress value.

4. The method according to claim 1, characterized in that In response to the trigger instruction, increasing the upper limit of the output current of the power module in the vehicle includes: When the vehicle is in the supercharging mode, in response to the trigger instruction, the upper limit value of the output current of the power module is increased.

5. The method according to claim 4, characterized in that When the vehicle is in the supercharging mode, before increasing the output current upper limit of the power module in response to the trigger instruction, the method further includes: When the coolant temperature is less than a first preset temperature, the vehicle is controlled to enter the supercharging mode.

6. The method according to claim 4, characterized in that The method further comprises: When the coolant temperature is greater than a second preset temperature, the vehicle is controlled to exit the supercharging mode.

7. The method according to claim 1, characterized in that The controlling the vehicle with the increased output current upper limit value includes: The output current of the power module is controlled to be limited within the boosted output current upper limit value, and the motor on the vehicle is controlled with the current within the boosted output current upper limit value.

8. A vehicle motor control device, characterized in that: include: A response module is configured to increase an output current upper limit value of a power module in the vehicle in response to a trigger instruction; The current upper limit value indicates the current boundary of the power module output, and the trigger instruction indicates to increase the speed of the vehicle; The control module is configured to control the vehicle with the increased output current upper limit value.

9. A vehicle, characterized in that: include: processor; a memory for storing processor-executable instructions; Wherein, the processor is configured to: Execute the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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