Motor control method, device, vehicle and storage medium

Abstract

The present application provides a control method, device, vehicle and storage medium for a motor, which is applied to the field of vehicles, and includes: when the motor is in a stalled condition, obtaining the three-phase duty cycle of the motor in the current cycle and the three-phase duty cycle in the previous cycle, and determining the final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle, so as to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor. The method can dynamically change the current distribution of each phase bridge arm of the motor by dynamically adjusting the three-phase duty cycle, so that the upper and lower bridge arms heat evenly, thereby improving the motor's stalling ability, so as to avoid overheating of a certain bridge arm during the stalling process, thereby extending the stalling time.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and more specifically, to a control method, a device, a vehicle and a storage medium for a motor in the field of vehicles. Background Art

[0002] With the rapid development of new energy vehicles, users' requirements for vehicle performance are constantly increasing, especially under complex road conditions, it is easy to encounter some emergencies that affect the vehicle's driving performance. For example, when the vehicle starts on a steep slope, it is easy to get stuck. After the vehicle enters the stuck condition, the motor cannot rotate, which will cause the three-phase current to change from AC to DC, causing the power devices in the controller to heat unevenly, causing a certain bridge arm to heat up severely, thus affecting the overall performance and reliability of the system.

[0003] In the related art, the MTPA control angle is mainly adjusted to make the three-phase currents as close to the same as possible, thereby avoiding severe heating of a bridge arm.

[0004] However, the above method is only applicable when the motor is not completely blocked. Once the motor is completely blocked, it is no longer applicable. At the same time, it cannot solve the problem of asymmetric heating of the upper and lower bridge arms, which needs to be solved urgently. Summary of the invention

[0005] The present application provides a motor control method, device, vehicle and storage medium. The method can dynamically change the current distribution of each phase bridge arm of the motor by dynamically adjusting the three-phase duty cycle, so that the upper and lower bridge arms are heated evenly, thereby improving the motor's stalling ability to avoid overheating of a bridge arm during the stalling process, thereby prolonging the stalling time.

[0006] In a first aspect, a method for controlling a motor is provided, the method comprising: determining whether the motor is in a stalled rotor condition; if the motor is in the stalled rotor condition, obtaining the three-phase duty cycle of the motor in a current cycle and the three-phase duty cycle in a previous cycle, and determining a final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle; determining a control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and controlling the motor according to the control signal of each phase bridge arm of the motor.

[0007] Through the above technical solution, the three-phase duty cycle can be dynamically adjusted to dynamically change the current distribution of each phase bridge arm of the motor, so that the upper and lower bridge arms heat evenly, thereby improving the motor's stalling ability to avoid overheating of a bridge arm during the stalling process, thereby extending the stalling time.

[0008] In combination with the first aspect, in some possible implementations, determining whether the motor is in the stalled condition includes: obtaining a current torque value of the motor and a current speed value of the motor; determining whether the current torque value of the motor is greater than a preset torque threshold and whether the current speed value of the motor is less than a preset speed threshold; if the current torque value is greater than the preset torque threshold and the current speed value is less than the preset speed threshold, determining that the motor is in the stalled condition.

[0009] Through the above technical solution, by judging whether the motor is in a stalled rotor condition, the three-phase duty cycle of the current cycle can be processed based on the stalled rotor capacity improvement strategy when the motor is in a stalled rotor condition, so that the processed three-phase duty cycle can make the heat of the upper and lower bridges evenly distributed, avoiding overheating of a phase bridge arm during the stalling process, and improving the controller's stalling capacity.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, determining the final three-phase duty cycle of the motor in the current cycle based on the three-phase duty cycle of the current cycle and the three-phase duty cycle in the previous cycle includes: obtaining the maximum duty cycle value, the minimum duty cycle value and the current duty cycle accumulated value among the three-phase duty cycles of the previous cycle; judging whether the minimum duty cycle value is less than the minimum preset duty cycle threshold; if the minimum duty cycle value is less than the minimum preset duty cycle threshold, obtaining a first duty cycle correction value based on the sum of the current duty cycle accumulated value and a first preset step size; and obtaining the final three-phase duty cycle of the current cycle based on the three-phase duty cycle of the current cycle and the first duty cycle correction value.

[0011] Through the above technical solution, in the process of stall capacity improvement strategy, based on the comparison between the minimum duty cycle value and the minimum preset duty cycle threshold, when the minimum duty cycle value is less than the minimum preset duty cycle threshold, it means that the minimum duty cycle value is too low and needs to be increased based on the first preset step size, so as to obtain the final three-phase duty cycle of the current cycle based on the increased-value first duty cycle correction value and the three-phase duty cycle of the current cycle.

[0012] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the minimum duty cycle value is less than the minimum preset duty cycle threshold, it also includes: if the minimum duty cycle value is greater than or equal to the minimum preset duty cycle threshold, then determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold; if the maximum duty cycle value is greater than the maximum preset duty cycle threshold, then obtaining a second duty cycle correction value based on the difference between the current duty cycle accumulated value and the second preset step size; and obtaining the final three-phase duty cycle of the current cycle based on the three-phase duty cycle of the current cycle and the second duty cycle correction value.

[0013] Through the above technical solution, in the process of stall capacity improvement strategy, based on the comparison between the maximum duty cycle value and the maximum preset duty cycle threshold, when the maximum duty cycle value is greater than the maximum preset duty cycle threshold, it means that the maximum duty cycle value is too high and needs to be subtracted based on the second preset step size, so as to obtain the final three-phase duty cycle of the current cycle based on the subtracted second duty cycle correction value and the three-phase duty cycle of the current cycle.

[0014] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold, it also includes: if the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold, then the final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle.

[0015] Through the above technical solution, in the process of stall capacity improvement strategy, based on the comparison between the maximum duty cycle value and the maximum preset duty cycle threshold, when the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold, it means that the maximum duty cycle value is in a stable range at this time, and there is no need to deduct based on the second preset step size. The final three-phase duty cycle of the current cycle can be directly obtained according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle.

[0016] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, when determining the final three-phase duty cycle of the motor in the current cycle, it also includes: using the first duty cycle correction value or the second duty cycle correction value to update the current duty cycle accumulated value.

[0017] Through the above technical solution, the current duty cycle accumulated value is updated based on the first duty cycle correction value or the second duty cycle correction value obtained, thereby improving the current distribution of each phase bridge arm of the motor, so that the heat of the upper and lower bridge arms is evenly distributed, avoiding overheating of a phase bridge arm during the stall process, and improving the stall capability of the controller.

[0018] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, after determining whether the motor is in a stalled rotor condition, it also includes: if the motor is not in the stalled rotor condition, determining the control signal of each phase bridge arm of the motor according to the three-phase duty cycle of the motor in the current cycle, and controlling the motor according to the control signal of each phase bridge arm of the motor.

[0019] Through the above technical solution, when the motor is not in the stalled rotor condition, the control signal of each phase bridge arm of the motor is directly determined according to the three-phase duty cycle of the motor in the current cycle, so that the heat of the upper and lower bridge arms is evenly distributed, avoiding overheating of a phase bridge arm during the stalling process, and improving the stalling capability of the controller.

[0020] In a second aspect, a control device for a motor is provided, the device comprising:

[0021] A judging module, used to judge whether the motor is in a stalled condition;

[0022] A determination module, configured to obtain the three-phase duty cycle of the motor in a current cycle and the three-phase duty cycle of the motor in a previous cycle if the motor is in the stalled rotor condition, and determine a final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle;

[0023] A control module is used to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor.

[0024] In conjunction with the second aspect, in some possible implementations, the determination module includes:

[0025] A first acquisition unit, used to acquire a current torque value of the motor and a current speed value of the motor;

[0026] A first judgment unit, used to judge whether the current torque value of the motor is greater than a preset torque threshold and whether the current speed value of the motor is less than a preset speed threshold;

[0027] A determination unit is used to determine that the motor is in the stalled condition if the current torque value is greater than the preset torque threshold and the current speed value is less than the preset speed threshold.

[0028] In combination with the second aspect and the foregoing implementations, in some possible implementations, the determining module includes:

[0029] A second acquisition unit, used to acquire a maximum duty cycle value, a minimum duty cycle value and a current duty cycle accumulated value among the three-phase duty cycles of the previous cycle;

[0030] A second judging unit, configured to judge whether the minimum duty cycle value is less than a minimum preset duty cycle threshold;

[0031] A first adding unit, configured to obtain a first duty cycle correction value according to a sum of the current duty cycle accumulated value and a first preset step length if the minimum duty cycle value is less than the minimum preset duty cycle threshold value;

[0032] The second adding unit is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the first duty cycle correction value.

[0033] In combination with the second aspect and the foregoing implementation manner, in some possible implementation manners, after determining whether the minimum duty cycle value is less than the minimum preset duty cycle threshold, the second determination unit further includes:

[0034] a judging subunit, configured to judge whether the maximum duty cycle value is greater than a maximum preset duty cycle threshold value if the minimum duty cycle value is greater than or equal to the minimum preset duty cycle threshold value;

[0035] A first acquisition subunit, configured to obtain a second duty cycle correction value according to a difference between the current duty cycle accumulated value and a second preset step length if the maximum duty cycle value is greater than the maximum preset duty cycle threshold;

[0036] The second acquisition subunit is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the second duty cycle correction value.

[0037] In combination with the second aspect and the above implementation manner, in some possible implementation manners, after determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold, the determination subunit further includes:

[0038] The acquisition component is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle if the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold.

[0039] In combination with the second aspect and the above implementations, in some possible implementations, when determining the final three-phase duty cycle of the motor in the current cycle, the acquisition component further includes:

[0040] An updating subcomponent is used to update the current duty cycle accumulated value using the first duty cycle correction value or the second duty cycle correction value.

[0041] In combination with the second aspect and the above implementations, in some possible implementations, after determining whether the motor is in a stalled rotor condition, the determination module further includes:

[0042] A control unit is used to determine the control signal of each phase bridge arm of the motor according to the three-phase duty cycle of the motor in the current cycle if the motor is not in the stalled condition, and control the motor according to the control signal of each phase bridge arm of the motor.

[0043] In a third aspect, a vehicle is provided, comprising the control method of the motor described in the above embodiment.

[0044] In a fourth aspect, a computer program product is provided, comprising: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0045] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code runs on a computer, the computer executes the method in the above-mentioned first aspect or any possible implementation manner of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A flow chart of a method for controlling a motor provided in an embodiment of the present application;

[0047] Figure 2 A schematic diagram of dynamic adjustment of the three-phase duty cycle of a motor according to an embodiment of the present application;

[0048] Figure 3 A flowchart of a strategy for improving the stall capacity according to an embodiment of the present application;

[0049] Figure 4 A schematic diagram of a three-phase duty ratio output by a control module and a three-phase duty ratio output by a locked-rotor capability enhancement strategy module according to an embodiment of the present application;

[0050] Figure 5 A schematic diagram of a simulation of the dynamic change of the current in each phase bridge arm of a motor according to an embodiment of the present application;

[0051] Figure 6 A block diagram of a control device for a motor provided in an embodiment of the present application;

[0052] Figure 7 A schematic diagram of the structure of a vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] The technical solution in the present application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" means two or more than two.

[0054] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0055] With the rapid development of new energy vehicles, more and more users are starting to use new energy vehicles. Therefore, users' requirements for the vehicle performance of new energy vehicles are also constantly increasing, especially in complex road conditions, where it is easy to encounter some emergencies that affect the vehicle's driving performance. For example, when a vehicle starts on a steep slope, it is easy to get stuck. After the vehicle enters the stuck condition, the motor cannot rotate, which will cause the three-phase current to change from AC to DC, and the six bridge arm power devices of the controller will change from being turned on in turn to being turned on with a fixed number of bridge arms, which will cause the power devices in the controller to heat unevenly. Especially when a certain bridge arm is severely heated, it will not only affect the overall performance and reliability of the system, but also cause damage to the controller. Therefore, there is a need for a method that can evenly distribute the heat of the upper and lower bridge arms of the controller without increasing the hardware cost, thereby improving the controller's ability to block rotation, so as to avoid overheating of a certain bridge arm during the blocking process, thereby prolonging the blocking time.

[0056] Figure 1 It is a schematic flow chart of a vehicle control method provided in an embodiment of the present application.

[0057] For example, Figure 1 As shown, the method includes:

[0058] In step S101, it is determined whether the motor is in a stalled condition.

[0059] Optionally, in one embodiment of the present application, determining whether the motor is in a stalled condition includes: obtaining a current torque value of the motor and a current speed value of the motor; determining whether the current torque value of the motor is greater than a preset torque threshold and whether the current speed value of the motor is less than a preset speed threshold; if the current torque value is greater than the preset torque threshold and the current speed value is less than the preset speed threshold, then determining that the motor is in a stalled condition.

[0060] Optionally, in one embodiment of the present application, after determining whether the motor is in a stalled condition, it also includes: if the motor is not in a stalled condition, determining the control signal of each phase bridge arm of the motor according to the three-phase duty cycle of the motor in the current cycle, and controlling the motor according to the control signal of each phase bridge arm of the motor.

[0061] Among them, the preset torque threshold and the preset speed threshold can be set by technical personnel in this field according to actual test requirements, or can be obtained through a limited number of computer simulations, or can be values ​​calibrated by motor parameters, and no specific limitation is made here.

[0062] Specifically, in order to solve the uneven heating of power devices when the motor is in a stalled condition, especially when a certain bridge arm is severely heated, the stalling time will be prolonged, thereby affecting the overall performance and reliability of the system. Therefore, a method is needed to evenly distribute the heat of the upper and lower bridge arms of the motor without increasing the hardware cost, thereby improving the motor's stalling ability and avoiding prolonging the stalling time when a certain bridge arm overheats during the stalling process.

[0063] Specifically, if Figure 2 As shown, the present application makes the current distribution of the upper and lower bridge arm power devices of the motor more uniform by dynamically adjusting the three-phase duty cycle, thereby avoiding overheating of a certain phase bridge arm and affecting the motor's stalling ability. Therefore, first, the three-phase duty cycle of the motor in the current cycle output by the MCU (Microcontroller Unit) control module is collected, which are the A-phase duty cycle DutyA, the B-phase duty cycle DutyB and the C-phase duty cycle DutyC; secondly, the working condition of the motor is determined to confirm whether the motor is in a stalled condition, so as to effectively control the motor according to whether the motor is in a stalled condition. The determination condition is to obtain the current torque value of the motor and the current speed value of the motor, and determine whether the current torque value of the motor is greater than the preset torque threshold T (for example, 200rpm) and whether the current speed value of the motor is less than the preset speed threshold n (for example, 0.8*peak torque). If the current torque value is greater than the preset torque threshold and the current speed value is less than the preset speed threshold, it is determined that the motor is in a stalled condition.

[0064] Furthermore, if the motor is not in a stalled condition, the DutyA, DutyB and DutyC output by the MCU control module are transmitted to the MCU logic processing module, and DutyA, DutyB and DutyC are processed based on the module processing performance, and then the control signal of each phase bridge arm of the motor is output. That is to say, after the MCU logic processing module processes DutyA, DutyB and DutyC, it generates a corresponding high-level signal or a low-level signal based on DutyA, DutyB and DutyC, and outputs it to the drive circuit to control the IGBT (Insulated Gate Bipolar Transistor) of the corresponding upper and lower bridge arms of each phase to turn on or off, thereby changing the current distribution of the upper and lower bridge arm IGBTs of the motor to balance the heat generated by the upper and lower bridge arms.

[0065] For example, after the MCU logic processing module processes DutyA, DutyB and DutyC, if a high-level signal is generated based on phase A and when the current direction is positive, a high-level signal is sent to the upper bridge arm of phase A of the motor to control the upper bridge arm IGBT to turn on, and a low-level signal is sent to the lower bridge arm of phase A of the motor to control the lower bridge arm IGBT to turn off. At the same time, based on the obtained size of the A-phase duty cycle, the continuous on time and continuous off time of the corresponding bridge arm IGBT are obtained. For example, if the calculated duty cycle is 50%, it means that in the IGBT of the A-phase bridge arm, half of the time is in the on state and the other half is in the off state in one cycle.

[0066] In step S102, if the motor is in a stalled condition, the three-phase duty cycle of the motor in the current cycle and the three-phase duty cycle in the previous cycle are obtained, and the final three-phase duty cycle of the motor in the current cycle is determined based on the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle.

[0067] Optionally, in one embodiment of the present application, the final three-phase duty cycle of the motor in the current cycle is determined based on the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle, including: obtaining the maximum duty cycle value, the minimum duty cycle value and the current duty cycle accumulated value among the three-phase duty cycles of the previous cycle; judging whether the minimum duty cycle value is less than the minimum preset duty cycle threshold; if the minimum duty cycle value is less than the minimum preset duty cycle threshold, obtaining a first duty cycle correction value based on the sum of the current duty cycle accumulated value and the first preset step size; and obtaining the final three-phase duty cycle of the current cycle based on the three-phase duty cycle of the current cycle and the first duty cycle correction value.

[0068] Among them, the minimum preset duty cycle threshold and the first preset step size can be set by technical personnel in this field according to actual test requirements, or can be obtained through a limited number of computer simulations, and are not specifically limited here.

[0069] Specifically, based on the judgment conditions of motor stall, if the motor is in a stall condition, the stall capacity improvement strategy is adopted for DutyA, DutyB and DutyC output by the MCU control module, so as to obtain the final three-phase duty cycle of the motor in the current cycle, namely DutyAend, DutyBend and DutyCend, based on DutyA, DutyB and DutyC processed by the stall capacity improvement strategy.

[0070] Specifically, if Figure 3As shown, when it is determined that the motor is in a stalled condition, first, the final three-phase duty cycle of the motor in the previous cycle, that is, DutyAend, DutyBend and DutyCend of the previous cycle, is obtained; secondly, the maximum duty cycle value DutyMax and the minimum duty cycle value DutyMin in DutyAend, DutyBend and DutyCend of the previous cycle are calculated. If the minimum duty cycle value is less than the minimum preset duty cycle threshold value DutyL, it means that the minimum duty cycle value is too low and has fallen below the minimum limit value. Therefore, it is necessary to increase the current duty cycle accumulated value DeltDutySumLast with the first preset step size DeltDuty. That is to say, the current duty cycle accumulated value DeltDutySumLast is multiplied by the first preset step size De ltDuty is added and calculated to obtain the first duty cycle correction value DeltDutySum, which is the new duty cycle accumulated value, which can be expressed as DeltDutySum=DeltDutySumLast+DeltDuty; finally, the final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the motor in the current cycle output by the MCU control module and the first duty cycle correction value, and the formula can be expressed as: the final A-phase duty cycle of the current cycle is DutyAend=DutyA+DeltDutySum, the final B-phase duty cycle of the current cycle is DutyBend=DutyB+DeltDutySum, and the final C-phase duty cycle of the current cycle is DutyCend=DutyC+DeltDutySum.

[0071] For example, in an embodiment of the present application, if the minimum preset duty cycle threshold DutyL is set to 0.2 and the first preset step size DeltDuty is set to 0.01, then when the minimum duty cycle value DutyMin is less than 0.2, the current duty cycle accumulated value DeltDutySumLast is added based on the step size value of the first preset step size DeltDuty being 0.01 to obtain the first duty cycle correction value DeltDutySum, so as to obtain the final three-phase duty cycle of the current cycle based on the first duty cycle correction value DeltDutySum and the three-phase duty cycle output by the MCU control module, wherein the specific values ​​of the first preset step size DeltDuty and the minimum preset duty cycle threshold DutyL can be adjusted by testing the heating conditions of the upper and lower bridge arms on the bench.

[0072] Optionally, in one embodiment of the present application, after determining whether the minimum duty cycle value is less than the minimum preset duty cycle threshold, it also includes: if the minimum duty cycle value is greater than or equal to the minimum preset duty cycle threshold, determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold; if the maximum duty cycle value is greater than the maximum preset duty cycle threshold, obtaining a second duty cycle correction value based on the difference between the current duty cycle accumulated value and the second preset step size; and obtaining the final three-phase duty cycle of the current cycle based on the three-phase duty cycle of the current cycle and the second duty cycle correction value.

[0073] Among them, the second preset step size and the maximum preset duty cycle threshold can be set by technical personnel in this field according to actual test requirements, or can be obtained through a limited number of computer simulations, and are not specifically limited here.

[0074] Specifically, Figure 3 As shown, if it is determined that the minimum duty cycle value DutyMin is greater than or equal to the minimum preset duty cycle threshold DutyL, it is further determined whether the maximum duty cycle value DutyMax is greater than the maximum preset duty cycle threshold DutyH. If the maximum duty cycle value DutyMax is greater than the maximum preset duty cycle threshold DutyH, it means that the maximum duty cycle value is too high and has exceeded the maximum limit value. Therefore, it is necessary to reduce the current duty cycle accumulated value DeltDutySumLast by the second preset step size DeltDuty. That is to say, the current duty cycle is increased by The difference between the duty cycle accumulated value DeltDutySumLast and the second preset step size DeltDuty is calculated to obtain the second duty cycle correction value DeltDutySum. The second duty cycle correction value is the new duty cycle accumulated value, which can be expressed as DeltDutySum=DeltDutySumLast-DeltDuty. Finally, the final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the motor in the current cycle output by the MCU control module and the second duty cycle correction value. To avoid redundancy, the formula is not discussed in detail here.

[0075] For example, in an embodiment of the present application, if the maximum preset duty cycle threshold DutyH is set to 0.8 and the second preset step size DeltDuty is set to 0.01, at this time, when the maximum duty cycle value DutyMax is greater than 0.8, the current duty cycle accumulated value DeltDutySumLast is difference calculated based on the step size of the second preset step size DeltDuty being 0.01, so as to obtain the second duty cycle correction value DeltDutySum, and to obtain the final three-phase duty cycle of the current cycle based on the second duty cycle correction value DeltDutySum and the three-phase duty cycle output by the MCU control module, wherein the specific values ​​of the second preset step size DeltDuty and the maximum preset duty cycle threshold DutyH can be adjusted by testing the heating conditions of the upper and lower bridge arms on the bench.

[0076] Optionally, in one embodiment of the present application, after determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold, it also includes: if the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold, then the final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle.

[0077] Specifically, Figure 3 As shown, if it is determined that the maximum duty cycle value DutyMax is less than or equal to the maximum preset duty cycle threshold DutyH, it indicates that the maximum duty cycle value DutyMax does not exceed the maximum preset duty cycle threshold DutyH of the limit, and there is no need to perform difference calculation based on the second preset step size DeltDuty, that is, DeltDutySum=DeltDutySumLast. At this time, the final three-phase duty cycle of the current cycle is directly obtained according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle, that is, the final A-phase duty cycle of the current cycle is DutyAend=DutyA+DeltDutySum, the final B-phase duty cycle of the current cycle is DutyBend=DutyB+DeltDutySum, and the final C-phase duty cycle of the current cycle is DutyCend=DutyC+DeltDutySum, wherein DeltDutySum here does not involve step size calculation.

[0078] Optionally, in one embodiment of the present application, when determining the final three-phase duty cycle of the motor in the current cycle, it also includes: updating the current duty cycle accumulated value using the first duty cycle correction value or the second duty cycle correction value.

[0079] Specifically, based on the discussion of the above specific embodiments, the final three-phase duty cycle of the current cycle needs to be continuously judged by the maximum duty cycle value DutyMax and the minimum duty cycle value DutyMin in the DutyAend, DutyBend and DutyCend of the previous cycle, respectively, and the maximum preset duty cycle threshold DutyH and the minimum preset duty cycle threshold DutyL, so that when the minimum duty cycle value DutyMin is less than the minimum preset duty cycle threshold DutyL, the first preset step size DeltDuty is used for addition calculation, and when the maximum duty cycle value DutyMax is greater than the maximum preset duty cycle threshold DutyH, the second preset step size DeltDuty is used for difference calculation, so as to obtain the calculated first duty cycle correction value and the second duty cycle correction value respectively, and update the current duty cycle accumulated value with the first duty cycle correction value and the second duty cycle correction value, so as to ensure the final current control accuracy of each phase bridge arm of the motor, so that the heat is more evenly distributed between the upper and lower bridge arms.

[0080] In step S103, a control signal of each phase bridge arm of the motor is determined according to the final three-phase duty cycle, and the motor is controlled according to the control signal of each phase bridge arm of the motor.

[0081] Specifically, Figure 4 and Figure 5 As shown, after DutyA, DutyB and DutyC output by the MCU control module are processed by the blocking capability improvement strategy discussed in the above specific embodiment, the final three-phase duty ratios DutyAend, DutyBend and DutyCend after the blocking capability improvement strategy are obtained, and DutyAend, DutyBend and DutyCend are transmitted to the MCU logic processing module, DutyAend, DutyBend and DutyCend are processed based on the module processing performance, and then the control signal of each phase bridge arm of the motor is output, that is, the control signal of the A-phase bridge arm, the B-phase bridge arm and the C-phase bridge arm of the motor is output, That is to say, after the MCU logic processing module processes DutyAend, DutyBend and DutyCend, it will generate a corresponding high-level signal or a low-level signal based on DutyAend, DutyBend and DutyCend, and output it to the drive circuit to control the IGBT of each corresponding upper and lower bridge arm to be turned on or off. This cycle is repeated, thereby changing the current distribution of the upper and lower bridge arm IGBTs of the motor based on the dynamic three-phase duty ratio DutyAend, DutyBend and DutyCend to balance the heat generated by the upper and lower bridge arms. The specific current control principle has been described in detail above and will not be discussed here to avoid redundancy.

[0082] Therefore, based on the above detailed discussion, the embodiments of the present application can achieve the following beneficial effects:

[0083] (1) Improving system reliability. The embodiment of the present application is applicable to the working condition where the motor is completely blocked. By dynamically adjusting the duty cycle, the conduction time of the upper bridge arm and the lower bridge arm of each phase is ensured to be more balanced, thereby avoiding the risk of overheating of a certain phase bridge arm and extending the service life of the IGBT.

[0084] (2) Improve system efficiency. By dynamically adjusting the duty cycle, the system can more accurately control the flow of current and reduce unnecessary energy loss.

[0085] (3) Improve the stall performance of the motor. This application does not increase the hardware cost, does not reduce the torque, and does not rely on the IGBT and diode temperature. By dynamically adjusting the duty cycle, it can better control the motor current and torque under stall conditions, ensuring that the motor can start smoothly and maintain a stable operating state.

[0086] In summary, according to the control method of the motor of the embodiment of the present application, when the motor is in a stalled condition, the three-phase duty cycle of the motor in the current cycle and the three-phase duty cycle in the previous cycle are obtained, and the final three-phase duty cycle of the motor in the current cycle is determined according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle, so as to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor. This method can dynamically change the current distribution of each phase bridge arm of the motor by dynamically adjusting the three-phase duty cycle, so that the upper and lower bridge arms heat evenly, thereby improving the motor's stalling ability, so as to avoid overheating of a certain bridge arm during the stalling process, thereby extending the stalling time.

[0087] Figure 6 It is a structural schematic diagram of a motor control device provided in an embodiment of the present application.

[0088] For example, Figure 6 As shown, the device may include: a judgment module 100 , a determination module 200 and a control module 300 .

[0089] The judging module 100 is used to judge whether the motor is in a stalled condition;

[0090] A determination module 200, for obtaining the three-phase duty cycle of the motor in a current cycle and the three-phase duty cycle of the motor in a previous cycle if the motor is in a stalled condition, and determining a final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle;

[0091] The control module 300 is used to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor.

[0092] Optionally, in one embodiment of the present application, the determination module 100 includes:

[0093] A first acquisition unit, used to acquire a current torque value and a current speed value of the motor;

[0094] A first judgment unit, used to judge whether the current torque value of the motor is greater than a preset torque threshold and whether the current speed value of the motor is less than a preset speed threshold;

[0095] The determination unit is used to determine that the motor is in a stalled condition if the current torque value is greater than a preset torque threshold and the current speed value is less than a preset speed threshold.

[0096] Optionally, in one embodiment of the present application, the determination module 200 includes:

[0097] The second acquisition unit is used to acquire the maximum duty cycle value, the minimum duty cycle value and the current duty cycle accumulated value of the three-phase duty cycle in the previous cycle;

[0098] A second judging unit, used to judge whether the minimum duty cycle value is less than a minimum preset duty cycle threshold;

[0099] A first adding unit, configured to obtain a first duty cycle correction value according to a sum of a current duty cycle accumulation value and a first preset step length if the minimum duty cycle value is less than a minimum preset duty cycle threshold value;

[0100] The second adding unit is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the first duty cycle correction value.

[0101] Optionally, in one embodiment of the present application, after determining whether the minimum duty cycle value is less than a minimum preset duty cycle threshold, the second determination unit further includes:

[0102] A judging subunit, configured to judge whether the maximum duty cycle value is greater than a maximum preset duty cycle threshold value if the minimum duty cycle value is greater than or equal to the minimum preset duty cycle threshold value;

[0103] A first acquisition subunit is used to obtain a second duty cycle correction value according to a difference between a current duty cycle accumulated value and a second preset step length if the maximum duty cycle value is greater than a maximum preset duty cycle threshold value;

[0104] The second acquisition subunit is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the second duty cycle correction value.

[0105] Optionally, in one embodiment of the present application, after determining whether the maximum duty cycle value is greater than a maximum preset duty cycle threshold, the determination subunit further includes:

[0106] The acquisition component is used to obtain the final three-phase duty cycle of the current cycle according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle if the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold.

[0107] Optionally, in one embodiment of the present application, when determining the final three-phase duty cycle of the motor in the current cycle, the obtaining means further includes:

[0108] The updating subcomponent is used to update the current duty cycle accumulated value using the first duty cycle correction value or the second duty cycle correction value.

[0109] Optionally, in one embodiment of the present application, after determining whether the motor is in a stalled condition, the determination module 100 further includes:

[0110] The control unit is used to determine the control signal of each phase bridge arm of the motor according to the three-phase duty cycle of the motor in the current cycle if the motor is not in a stalled condition, and control the motor according to the control signal of each phase bridge arm of the motor.

[0111] In summary, according to the control device of the motor of the embodiment of the present application, when the motor is in a stalled condition, the three-phase duty cycle of the motor in the current cycle and the three-phase duty cycle in the previous cycle are obtained, and the final three-phase duty cycle of the motor in the current cycle is determined according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle, so as to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor. This method can dynamically change the current distribution of each phase bridge arm of the motor by dynamically adjusting the three-phase duty cycle, so that the upper and lower bridge arms heat evenly, thereby improving the motor's stalling ability, so as to avoid overheating of a certain bridge arm during the stalling process, thereby extending the stalling time.

[0112] Figure 7 A schematic structural diagram of a vehicle provided in an embodiment of the present application.

[0113] It should be understood that the above-described method can be applied to Figure 7 In a vehicle of the structure shown.

[0114] In addition, an embodiment of the present application also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute the motor control method provided by the embodiment of the present application.

[0115] Furthermore, the device also includes: a communication interface 703 for communication between the memory 701 and the processor 702 .

[0116] In this embodiment, the functional modules of the device can be divided according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0117] It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0118] It should be understood that the device provided in this embodiment is used to execute the above-mentioned control method of a motor, and thus can achieve the same effect as the above-mentioned implementation method.

[0119] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a vehicle, the processing module may be used to control and manage the actions of the vehicle. The storage module may be used to support the vehicle in executing mutual program codes, etc.

[0120] The processing module may be a processor 702 or a controller, which may implement or execute various exemplary logic blocks, modules and circuits disclosed in the present application. The processor 702 may also be a combination that implements a computing function, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory 701.

[0121] In addition, the device provided in the embodiments of the present application may specifically be a chip, a component or a module, and the chip may include a connected processor 702 and a memory 701; wherein the memory 701 is used to store instructions, and when the processor calls and executes the instructions, the chip can execute the motor control method provided in the above embodiments.

[0122] This embodiment also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement a motor control method provided in the above embodiment.

[0123] This embodiment further provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement a motor control method provided in the above embodiment.

[0124] Among them, the device, computer-readable storage medium, computer program product or chip provided in this embodiment is used to execute the corresponding method provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method provided above, and will not be repeated here.

[0125] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0126] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0127] The above contents are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling a motor, characterized in that: The method comprises: Determining whether the motor is in a stalled condition; If the motor is in the stalled condition, the three-phase duty cycle of the motor in the current cycle and the three-phase duty cycle in the previous cycle are obtained, and the final three-phase duty cycle of the motor in the current cycle is determined according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle; The control signal of each phase bridge arm of the motor is determined according to the final three-phase duty cycle, and the motor is controlled according to the control signal of each phase bridge arm of the motor.

2. The method according to claim 1, characterized in that The determining whether the motor is in the stalled operating condition includes: Obtaining a current torque value of the motor and a current speed value of the motor; Determine whether the current torque value of the motor is greater than a preset torque threshold and whether the current speed value of the motor is less than a preset speed threshold; If the current torque value is greater than the preset torque threshold and the current speed value is less than the preset speed threshold, it is determined that the motor is in the stalled condition.

3. The method according to claim 1, characterized in that: Determining the final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle in the previous cycle comprises: Obtaining the maximum duty cycle value, the minimum duty cycle value and the current duty cycle accumulated value among the three-phase duty cycles of the previous cycle; Determining whether the minimum duty cycle value is less than a minimum preset duty cycle threshold; If the minimum duty cycle value is less than the minimum preset duty cycle threshold, a first duty cycle correction value is obtained according to the sum of the current duty cycle accumulated value and the first preset step length; The final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the current cycle and the first duty cycle correction value.

4. The method according to claim 3, characterized in that After determining whether the minimum duty cycle value is less than the minimum preset duty cycle threshold, the method further includes: If the minimum duty cycle value is greater than or equal to the minimum preset duty cycle threshold, determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold; If the maximum duty cycle value is greater than the maximum preset duty cycle threshold, a second duty cycle correction value is obtained according to the difference between the current duty cycle accumulated value and the second preset step length; The final three-phase duty ratio of the current cycle is obtained according to the three-phase duty ratio of the current cycle and the second duty ratio correction value.

5. The method according to claim 4, characterized in that After determining whether the maximum duty cycle value is greater than the maximum preset duty cycle threshold, the method further includes: If the maximum duty cycle value is less than or equal to the maximum preset duty cycle threshold, the final three-phase duty cycle of the current cycle is obtained according to the three-phase duty cycle of the current cycle and the accumulated value of the current duty cycle.

6. The method according to claim 5, characterized in that When determining the final three-phase duty cycle of the motor in the current cycle, it also includes: The current duty cycle accumulated value is updated using the first duty cycle correction value or the second duty cycle correction value.

7. The method according to claim 1, characterized in that After determining whether the motor is in a stalled rotor condition, the method further includes: If the motor is not in the stalled condition, the control signal of each phase bridge arm of the motor is determined according to the three-phase duty cycle of the motor in the current cycle, and the motor is controlled according to the control signal of each phase bridge arm of the motor.

8. A control device for a motor, characterized in that: The device comprises: A judging module, used to judge whether the motor is in a stalled condition; A determination module, configured to obtain the three-phase duty cycle of the motor in a current cycle and the three-phase duty cycle of the motor in a previous cycle if the motor is in the stalled rotor condition, and determine a final three-phase duty cycle of the motor in the current cycle according to the three-phase duty cycle of the current cycle and the three-phase duty cycle of the previous cycle; A control module is used to determine the control signal of each phase bridge arm of the motor according to the final three-phase duty cycle, and control the motor according to the control signal of each phase bridge arm of the motor.

9. A vehicle, characterized in that: The vehicle comprises: a method for controlling a motor as described in any one of claims 1 to 7 above.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 7 is implemented.

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