Motor control methods and control devices, motor controllers, storage media

Abstract

This invention discloses a motor control method and control device, a motor controller, and a storage medium. The method includes: acquiring the motor's feedback speed during constant power operation; determining that when the feedback speed is higher than a first speed threshold, acquiring a speed loop control quantity based on a second speed threshold and the feedback speed, wherein the second speed threshold is greater than the first speed threshold; and controlling the motor to operate at a constant speed by using the second speed threshold as the setpoint for the speed loop and the speed loop control quantity as the initial control quantity for the speed loop. This method not only effectively avoids motor damage due to excessive speed but also achieves a smooth transition from constant power operation to constant speed operation.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a motor control method, a computer-readable storage medium, a motor controller, and a motor control device. Background Art

[0002] Currently, high-speed and miniaturized brushless DC motors are being used more and more widely, especially in the field of small power tools (such as handheld vacuum cleaners). When small power tools are powered by batteries, the battery voltage gradually decreases over time. In order to ensure that the device can output constant power, a constant power control strategy needs to be introduced during the battery voltage drop.

[0003] In related technologies, for motors with constant power control, when the load becomes lighter due to operating conditions, the motor speed will rise rapidly. However, prolonged high-speed operation of the motor will damage the rotor system and threaten the user's safety. Summary of the Invention

[0004] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to provide a motor control method that, when the motor speed increases to a certain level during constant power operation, controls the motor to operate at a constant speed, effectively preventing damage to the motor due to excessive speed, and simultaneously achieving a smooth transition from constant power operation to constant speed operation.

[0005] A second objective of this invention is to provide a computer-readable storage medium.

[0006] The third objective of this invention is to provide a motor controller.

[0007] The fourth objective of this invention is to provide a motor control device.

[0008] To achieve the above objectives, a first aspect of the present invention provides a motor control method, comprising: acquiring the feedback speed of the motor during constant power operation; when the feedback speed is determined to be higher than a first speed threshold, acquiring a speed loop control quantity based on a second speed threshold and the feedback speed, wherein the second speed threshold is greater than the first speed threshold; and when the feedback speed is determined to be higher than the second speed threshold, controlling the motor to operate at a constant speed by using the second speed threshold as the setpoint of the speed loop and the speed loop control quantity as the initial control quantity of the speed loop.

[0009] According to the motor control method of the present invention, during the process of controlling the motor to operate at constant power, the feedback speed of the motor is obtained, and when the feedback speed is higher than a first speed threshold, a speed loop control quantity is obtained based on a second speed threshold and the feedback speed. When the feedback speed is higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to operate at constant speed. This not only effectively avoids damage to the motor due to excessive speed, but also achieves a smooth switch from constant power operation to constant speed operation.

[0010] According to one embodiment of the present invention, obtaining a speed loop control quantity based on a second speed threshold and a feedback speed includes: obtaining the difference between the second speed threshold and the feedback speed; adjusting the difference using a speed loop to obtain an adjustment quantity; and accumulating the adjustment quantity to obtain a speed loop control quantity.

[0011] According to an embodiment of the present invention, the method further includes: during the process of controlling the motor to run at a constant speed, acquiring the time of constant speed operation and the control quantity of the power loop; and when it is determined that the time is lower than the time threshold and the control quantity of the speed loop is higher than the control quantity of the power loop, controlling the motor to run at a constant power.

[0012] According to one embodiment of the present invention, the method further includes: when the time is determined to be not less than a time threshold, controlling the motor to reduce speed or stop.

[0013] According to one embodiment of the present invention, the time threshold is determined based on at least one of the motor's temperature rise, heat dissipation, and rotor load.

[0014] According to one embodiment of the present invention, the control quantity of the power loop is the ratio of the target power to the DC bus voltage.

[0015] To achieve the above objectives, a second aspect of the present invention provides a computer-readable storage medium storing a motor control program thereon, which, when executed by a processor, implements the above-described motor control method.

[0016] According to the computer-readable storage medium of the present invention, by executing the above-described motor control method, not only can damage to the motor due to excessive speed be effectively avoided, but a smooth switching of the motor from constant power operation to constant speed operation is also achieved.

[0017] To achieve the above objectives, a third aspect of the present invention provides a motor controller, comprising: a memory, a processor, and a motor control program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described motor control method.

[0018] According to the embodiment of the present invention, by executing the above-described motor control method, the motor controller can not only effectively prevent the motor from being damaged due to excessive speed, but also achieve a smooth switching of the motor from constant power operation to constant speed operation.

[0019] To achieve the above objectives, a fourth aspect of the present invention provides a motor control device, comprising: an acquisition module for acquiring the feedback speed of the motor; and a control module for, during the process of controlling the motor to operate at constant power, when it is determined that the feedback speed is higher than a first speed threshold, acquiring a speed loop control quantity based on a second speed threshold and the feedback speed, and when it is determined that the feedback speed is higher than the second speed threshold, controlling the motor to operate at constant speed using the second speed threshold as the setpoint of the speed loop and the speed loop control quantity as the initial control quantity of the speed loop, wherein the second speed threshold is greater than the first speed threshold.

[0020] According to the motor control device of the present invention, when the feedback speed of the motor is determined to be higher than the first speed threshold during the constant power operation of the motor by the control module, the speed loop control quantity is obtained according to the second speed threshold and the feedback speed. When the feedback speed is determined to be higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to run at a constant speed. This not only effectively avoids damage to the motor due to excessive speed, but also realizes a smooth switch from constant power operation to constant speed operation of the motor.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of a motor control method according to an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of a motor control system according to an embodiment of the present invention;

[0024] Figure 3 This is a flowchart illustrating a motor control method according to another embodiment of the present invention;

[0025] Figure 4 This is a flowchart illustrating a motor control method according to yet another embodiment of the present invention;

[0026] Figure 5 This is a block diagram of a motor controller according to an embodiment of the present invention;

[0027] Figure 6 This is a block diagram of a motor control device according to an embodiment of the present invention. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] The following description, with reference to the accompanying drawings, outlines an embodiment of the motor control method, a computer-readable storage medium, a motor controller, and a motor control device proposed in this invention.

[0030] Figure 1 This is a schematic flowchart illustrating a motor control method according to an embodiment of the present invention. (Reference) Figure 1 As shown, the motor control method may include the following steps:

[0031] Step S1: During the constant power operation of the motor, obtain the feedback speed of the motor.

[0032] It should be noted that constant power operation of a motor means that the output power of the motor remains basically unchanged during operation, that is, the output power is basically the same as the target power, and the output torque of the motor decreases as the motor speed increases.

[0033] In an embodiment of the present invention, during the process of controlling the motor to operate at constant power, such as Figure 2 As shown, the power loop and current loop of the motor control system are connected. At this time, the power loop can generate a control quantity based on the target power and input the control quantity to the current loop. The current loop then performs subsequent control to achieve constant power operation of the motor.

[0034] In some embodiments, the control quantity of the power loop is the ratio of the target power to the DC bus voltage.

[0035] Specifically, when it is necessary to control the motor to operate at constant power, the target power is obtained. This target power can be the power set by the user or the power automatically generated by the system based on control requirements; there are no specific restrictions here. After obtaining the target power, it is input to the power loop, and at the same time, the DC bus voltage is detected through the voltage detection circuit, such as... Figure 2 As shown, the DC bus voltage refers to the voltage at the DC input terminal of the inverter, and the DC bus voltage is input to the power loop. Then, the power loop divides the target power by the DC bus voltage to obtain the ratio between the two. This ratio is the control quantity of the power loop, that is, the given current, and is input to the current loop. The current loop implements subsequent control based on the given current to achieve constant power operation of the motor.

[0036] During constant power operation of the motor, the feedback speed of the motor is acquired in real time. Optionally, a position sensor can be installed inside the motor to detect the feedback speed; or, in Figure 2 The inverter shown is equipped with a voltage detection circuit at its AC output terminal. The voltage detection circuit detects the zero-crossing point of the motor's back EMF and estimates the motor's feedback speed based on the zero-crossing point of the back EMF.

[0037] Step S2: When the feedback speed is higher than the first speed threshold, the speed loop control quantity is obtained based on the second speed threshold and the feedback speed, wherein the second speed threshold is greater than the first speed threshold.

[0038] It should be noted that the first speed threshold and the second speed threshold can be set according to the specific performance parameters of the motor, and the second speed threshold is also used as the target speed when the motor is running at a constant speed.

[0039] Specifically, during constant power operation of the motor, when the load on the motor becomes lighter due to the influence of operating conditions, the feedback speed of the motor will increase. When it rises to a certain level, such as exceeding the first speed threshold, the motor continues to operate at constant power and enters the speed loop buffer area. That is, the second speed threshold and the feedback speed are used as the input of the speed loop. At this time, the speed loop only obtains the speed loop control quantity based on the second speed threshold and the feedback speed, but the speed loop does not participate in the control of the motor.

[0040] Optionally, in some embodiments, obtaining the speed loop control quantity based on the second speed threshold and the feedback speed includes: obtaining the difference between the second speed threshold and the feedback speed; adjusting the difference using the speed loop to obtain an adjustment quantity; and accumulating the adjustment quantity to obtain the speed loop control quantity.

[0041] Specifically, when the feedback speed is higher than the first speed threshold, the motor continues to operate at constant power. At the same time, the speed loop is in a state of only calculating and not controlling. At this time, the speed loop obtains the speed difference between the second speed threshold and the feedback speed, and performs PI (Proportional Integral) or PID (Proportion Integration Differentiation) adjustment on the speed difference to obtain the adjustment amount. The obtained adjustment amounts are then accumulated to obtain the speed loop control amount.

[0042] Optionally, the speed loop may include an incremental PI or PID controller, but regardless of the controller used, the final control output of the speed loop is a full-value output.

[0043] Taking the speed loop including an incremental PID controller as an example. The output of the incremental PID controller is shown in formula (1):

[0044] Δu(k)=Kp*[e(k)-e(k-1)]+Ki*e(k)+Kd*[e(k)-2e(k-1)-e(k-2)] (1)

[0045] Where Δu(k) is the output of the incremental PID controller at time k, Kp is the proportional coefficient, Ki is the integral coefficient, Kd is the derivative coefficient, and e(k), e(k-1), and e(k-2) are the speed differences between the second speed threshold and the feedback speed at times k, k-1, and k-2, respectively.

[0046] Since the speed loop output is a full-quantity output, after obtaining the output Δu(k) of the incremental PID controller at time k, the output Δu(k) is accumulated to obtain the speed loop control quantity.

[0047] It should be noted that the speed loop can also be a positional PI or PID controller. Since the incremental PI or PID controller outputs a full value, the output adjustment values ​​do not need to be superimposed, as long as the incremental PI or PID controller is in the calculation state. Taking a speed loop including a positional PID controller as an example, the output of the positional PID controller is shown in formula (2):

[0048]

[0049] Where u(k) is the output of the position PID controller at time k, Kp is the proportional coefficient, Ki is the integral coefficient, Kd is the derivative coefficient, and e(k) and e(k-1) are the speed differences between the second speed threshold and the feedback speed at times k and k-1, respectively.

[0050] Step S3: When the feedback speed is higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to run at a constant speed.

[0051] It should be noted that constant speed operation of the motor means that the feedback speed remains basically unchanged during the motor's operation, that is, the feedback speed is basically consistent with the target speed, which is the second speed threshold. In other words, when the motor's feedback speed increases to the second speed threshold, the second speed threshold is used as the target speed to control the motor to operate at a constant speed, so as to avoid the motor speed from continuing to increase and remaining at a very high speed for a long time, which could damage the motor's rotor system.

[0052] Specifically, during constant power operation of the motor, when the feedback speed exceeds the second speed threshold, the connection between the power loop and the current loop of the motor control system is disconnected, and the speed loop is connected to the current loop, at which point the speed loop begins to participate in motor control. At the start of control, the speed loop control quantity calculated in step S2 is used as the initial control quantity of the speed loop and input to the current loop. Subsequent control is then performed through the current loop to achieve a smooth transition from constant power operation to constant speed operation. The second speed threshold is then used as the target speed input to the speed loop as a setpoint to control the motor to operate at constant speed. Specifically, during constant speed operation, the speed loop acquires the speed difference between the second speed threshold and the feedback speed, and performs PI or PID regulation on the speed difference to output a control quantity. This control quantity is then input to the current loop for subsequent control, achieving constant speed control of the motor.

[0053] In the above embodiments, when the motor is running at constant power, if the feedback speed of the motor is higher than the first speed threshold, the speed loop is kept in a continuous calculation state while the motor continues to run at constant power. When the feedback speed is higher than the second speed threshold, the calculation result is used as the initial control quantity of the speed loop, and the second speed threshold is used as the setpoint to control the motor to run at constant speed. This not only effectively avoids damage to the motor due to excessive speed, but also achieves a smooth switch from constant power operation to constant speed operation, improving the safety and reliability of motor operation.

[0054] Further reference Figure 3 As shown, the above-mentioned motor control method may further include the following steps:

[0055] Step S4: During the process of controlling the motor to run at a constant speed, obtain the time of constant speed operation and the control quantity of the power loop.

[0056] Specifically, when the motor is running at a constant speed, the time of constant speed operation can be recorded by a timer, and the control quantity of the power loop can be obtained at the same time. That is to say, when the motor is running at a constant speed, the power loop is in a state of only calculating and not participating in control. At this time, the power loop can calculate the control quantity based on the target power and the DC bus voltage, that is, divide the target power by the DC bus voltage to obtain the control quantity.

[0057] Step S5: When the time is lower than the time threshold and the control quantity of the speed loop is higher than the control quantity of the power loop, control the motor to run at constant power.

[0058] In other words, if the control quantity of the speed loop is higher than that of the power loop in a short period of time, it means that the motor load has returned to normal. At this time, disconnect the connection between the speed loop and the current loop of the motor control system, and connect the power loop and the current loop to control the motor to run at constant power.

[0059] Optionally, in some embodiments, the difference between the control quantity of the speed loop and the control quantity of the power loop can be obtained, and when the control quantity of the speed loop is higher than the control quantity of the power loop, the difference is less than a preset threshold, and the time is less than a time threshold, the motor is controlled to run at constant power. The difference can be set to a maximum value that does not impact the switching of motor operation, so as to achieve a smooth switching of the motor from constant speed operation to constant power operation.

[0060] It should be noted that the time threshold can be determined based on the motor's performance parameters, such as the motor's temperature rise, heat dissipation, and rotor load.

[0061] Step S6: When the time is determined to be no less than the time threshold, control the motor to reduce speed or stop.

[0062] In other words, if the control quantity of the speed loop is always lower than that of the power loop for a long period of time, it means that the motor load has not recovered and may have been in a light load state. At this time, the motor can be controlled to run at a reduced speed or be stopped to avoid the motor running at a light load and high speed for a long time.

[0063] As a specific example, such as Figure 4 As shown, the motor control method may include the following steps:

[0064] Step S301: Control the motor to operate at constant power.

[0065] Step S302: Obtain the feedback speed of the motor.

[0066] Step S303: Determine whether the feedback speed is higher than the first speed threshold. If yes, proceed to step S304; otherwise, return to step S301.

[0067] Step S304: Obtain the speed loop control quantity based on the second speed threshold and the feedback speed.

[0068] Step S305: Determine whether the feedback speed is higher than the second speed threshold. If yes, proceed to step S306; otherwise, return to step S301.

[0069] Step S306: Control the motor to run at a constant speed.

[0070] Step S307: Obtain the constant speed operation time and the control quantity of the power loop.

[0071] Step S308: Determine whether the constant speed operation time is lower than the time threshold. If yes, proceed to step S309; ​​otherwise, proceed to step S311.

[0072] Step S309: Determine whether the control quantity of the speed loop is higher than the control quantity of the power loop. If yes, proceed to step S310; otherwise, return to step S306.

[0073] Step S310: Control the motor to operate at constant power.

[0074] Step S311: Control the motor to reduce speed or stop.

[0075] In summary, the motor control method according to the embodiments of the present invention acquires the feedback speed of the motor during constant power operation, and when the feedback speed is higher than a first speed threshold, acquires a speed loop control quantity based on a second speed threshold and the feedback speed. When the feedback speed is higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to operate at constant speed. This not only ensures the safety and reliability of the motor rotor system operation when the motor operates at constant power and the speed spikes due to extreme working conditions and other factors, but also achieves a smooth switch from constant power operation to constant speed operation, reducing the impact of control mode switching.

[0076] Corresponding to the above embodiments, the present invention also proposes a computer-readable storage medium.

[0077] The computer-readable storage medium of this invention stores a motor control program thereon, which, when executed by a processor, implements the motor control method described above.

[0078] According to the computer-readable storage medium of the present invention, by executing the above-described motor control method, not only can damage to the motor due to excessive speed be effectively avoided, but a smooth switching of the motor from constant power operation to constant speed operation is also achieved.

[0079] Corresponding to the above embodiments, the present invention also proposes a motor controller.

[0080] Figure 5 This is a block diagram of a motor controller according to an embodiment of the present invention.

[0081] like Figure 5 As shown, the motor controller 100 of this embodiment includes: a memory 110, a processor 120, and a motor control program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the program, it implements the above-described motor control method.

[0082] According to the embodiment of the present invention, by executing the above-described motor control method, the motor controller can not only effectively prevent the motor from being damaged due to excessive speed, but also achieve a smooth switching of the motor from constant power operation to constant speed operation.

[0083] Corresponding to the above embodiments, the present invention also proposes a motor control device.

[0084] Figure 6 This is a block diagram of a motor control device according to an embodiment of the present invention.

[0085] like Figure 6 As shown, the motor control device 200 of this embodiment may include: an acquisition module 210 and a control module 220.

[0086] The acquisition module 210 is used to acquire the feedback speed of the motor. The control module 220 is used to, during the process of controlling the motor to operate at constant power, when it is determined that the feedback speed is higher than a first speed threshold, acquire the speed loop control quantity based on a second speed threshold and the feedback speed, and when it is determined that the feedback speed is higher than the second speed threshold, use the second speed threshold as the setpoint of the speed loop and the speed loop control quantity as the initial control quantity of the speed loop to control the motor to operate at constant speed, wherein the second speed threshold is greater than the first speed threshold.

[0087] According to one embodiment of the present invention, the control module 220 obtains a speed loop control quantity based on a second speed threshold and a feedback speed, specifically used to: obtain the difference between the second speed threshold and the feedback speed; adjust the speed loop to obtain an adjustment quantity based on the difference; and accumulate the adjustment quantity to obtain a speed loop control quantity.

[0088] According to one embodiment of the present invention, the control module 220 is further configured to, during the process of controlling the motor to run at a constant speed, acquire the time of constant speed operation and the control quantity of the power loop; and when it is determined that the time is lower than the time threshold and the control quantity of the speed loop is higher than the control quantity of the power loop, control the motor to run at a constant power.

[0089] According to one embodiment of the present invention, the control module 220 is further configured to control the motor to reduce speed or stop when the time is determined to be not less than a time threshold.

[0090] According to one embodiment of the present invention, the time threshold is determined based on at least one of the motor's temperature rise, heat dissipation, and rotor load.

[0091] According to one embodiment of the present invention, the control quantity of the power loop is the ratio of the target power to the DC bus voltage.

[0092] It should be noted that for details not disclosed in the motor control device of this embodiment, please refer to the details disclosed in the motor control method of this embodiment, which will not be repeated here.

[0093] According to the motor control device of the present invention, when the feedback speed of the motor is determined to be higher than the first speed threshold during the constant power operation of the motor by the control module, the speed loop control quantity is obtained according to the second speed threshold and the feedback speed. When the feedback speed is determined to be higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to run at a constant speed. This not only effectively avoids damage to the motor due to excessive speed, but also realizes a smooth switch from constant power operation to constant speed operation of the motor.

[0094] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0095] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0096] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0099] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A motor control method, characterized in that, include: During the process of controlling the motor to operate at constant power, the feedback speed of the motor is obtained; When the feedback speed is determined to be higher than the first speed threshold, the speed loop control quantity is obtained based on the second speed threshold and the feedback speed, wherein the second speed threshold is greater than the first speed threshold. When the feedback speed is determined to be higher than the second speed threshold, the second speed threshold is used as the setpoint of the speed loop and the speed loop control quantity is used as the initial control quantity of the speed loop to control the motor to run at a constant speed. During the process of controlling the motor to run at a constant speed, the time of constant speed operation and the control quantity of the power loop are obtained; When the time is determined to be lower than the time threshold and the control quantity of the speed loop is higher than the control quantity of the power loop, the motor is controlled to operate at constant power.

2. The method according to claim 1, characterized in that, The step of obtaining the speed loop control quantity based on the second speed threshold and the feedback speed includes: Obtain the difference between the second speed threshold and the feedback speed; The adjustment amount is obtained by adjusting the speed loop of the difference; The speed loop control quantity is obtained by accumulating the adjustment amount.

3. The method according to claim 1, characterized in that, The method further includes: When the time is determined to be no less than the time threshold, the motor is controlled to reduce speed or stop.

4. The method according to claim 1, characterized in that, The time threshold is determined based on at least one of the motor's temperature rise, heat dissipation, and rotor load.

5. The method according to claim 1, characterized in that, The control quantity of the power loop is the ratio of the target power to the DC bus voltage.

6. A computer-readable storage medium, characterized in that, It stores a motor control program, which, when executed by a processor, implements the motor control method according to any one of claims 1-5.

7. A motor controller, characterized in that, include: The system includes a memory, a processor, and a motor control program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the motor control method according to any one of claims 1-5.

8. A motor control device, characterized in that, include: An acquisition module is used to acquire the feedback speed of the motor; The control module is configured to, during the process of controlling the motor to operate at constant power, determine when the feedback speed is higher than a first speed threshold, obtain a speed loop control quantity based on a second speed threshold and the feedback speed, and when the feedback speed is determined to be higher than the second speed threshold, use the second speed threshold as the setpoint of the speed loop and the speed loop control quantity as the initial control quantity of the speed loop to control the motor to operate at constant speed, wherein the second speed threshold is greater than the first speed threshold; during the process of controlling the motor to operate at constant speed, obtain the time of constant speed operation and the control quantity of the power loop; and when the time is lower than a time threshold and the control quantity of the speed loop is higher than the control quantity of the power loop, control the motor to operate at constant power.

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