Motor control method and control device, motor controller, storage medium

Abstract

A motor control method and control device, a motor controller, and a storage medium, wherein the motor control method includes, in a process of controlling a motor to operate at constant power, a step (S1) of acquiring a feedback rotational speed of the motor, and, when it is determined that the feedback rotational speed is higher than a first rotational speed threshold, a step (S2) of acquiring a rotational speed loop control variable by a second rotational speed threshold higher than the first rotational speed threshold and the feedback rotational speed, and, when it is determined that the feedback rotational speed is higher than the second rotational speed threshold, a step (S3) of setting the second rotational speed threshold as a default variable of the rotational speed loop, setting the rotational speed loop control variable as an initial control variable of the rotational speed loop, and controlling the motor to operate at a constant rotational speed.

Description

Technical Field

[0001] This disclosure claims the priority of a Chinese patent application with application number 202210217485.4 and invention title "Motor Control Method and Control Device, Motor Controller, Storage Medium", which was filed on March 7, 2022, and the entire content thereof is incorporated into this disclosure by reference.

[0002] This disclosure relates to the technical field of motor control, and particularly to a motor control method, a computer-readable storage medium, a motor controller, and a motor control device.

Background Art

[0003] Currently, high-speed and miniaturized brushless DC motors are being increasingly widely applied, especially in the field of small power tools (such as handheld vacuum cleaners, etc.). When a small power tool is powered by a battery, the voltage of the battery gradually decreases as the usage time changes. In order to output a certain amount of power to the device, it is necessary to introduce a constant power control policy during the process when the battery voltage is decreasing.

[0004] In related technologies, for a motor with constant power control, when the load becomes lighter due to the influence of the operating conditions, the rotational speed of the motor increases rapidly. If the motor operates at a high rotational speed for a long time, it may damage the rotor system of the motor and also threaten the safety of the user during use.

Summary of the Invention

Problems to be Solved by the Invention

[0005] This disclosure aims to solve, to at least to a certain extent, one of the technical problems in the related technology. Therefore, the first object of this disclosure is to provide a motor control method that controls the motor to operate at a constant rotational speed when the rotational speed of the motor rises to a certain level during constant power operation, thereby effectively avoiding damage caused by excessively high rotational speeds and enabling a smooth transition from constant power operation to constant rotational speed operation of the motor.

[0006] The second object of this disclosure is to provide a computer-readable storage medium.

[0007] The third object of this disclosure is to provide a motor controller.

[0008] A fourth object of this disclosure is to provide a motor control device. [Means for solving the problem]

[0009] To achieve the above objectives, an embodiment of the first aspect of this disclosure provides a motor control method that includes the steps of: obtaining the feedback rotational speed of a motor in the process of controlling the motor to operate it at a constant power; obtaining a rotational speed loop control amount using a second rotational speed threshold greater than the first rotational speed threshold and the feedback rotational speed when it is determined that the feedback rotational speed is higher than a first rotational speed threshold; and controlling the motor to operate it at a constant rotational speed when it is determined that the feedback rotational speed is higher than the second rotational speed threshold, setting the second rotational speed threshold as a predetermined amount for the rotational speed loop and setting the rotational speed loop control amount as an initial control amount for the rotational speed loop.

[0010] According to the motor control method in the embodiment of this disclosure, in the process of controlling the motor to operate at a constant power, the motor's feedback rotational speed is obtained, and when the feedback rotational speed is higher than a first rotational speed threshold, a rotational speed loop control amount is obtained using the second rotational speed threshold and the feedback rotational speed. When the feedback rotational speed is higher than the second rotational speed threshold, the second rotational speed threshold is set as the default amount of the rotational speed loop, and the rotational speed loop control amount is set as the initial control amount of the rotational speed loop. By controlling the motor to operate at a constant rotational speed, it is possible to effectively avoid damage caused by excessively high motor rotational speed, and to achieve a smooth transition from constant power operation to constant rotational speed operation of the motor.

[0011] According to one embodiment of the present disclosure, the step of obtaining a rotation speed loop control amount using a second rotation speed threshold and a feedback rotation speed includes obtaining a difference between the second rotation speed threshold and the feedback rotation speed, performing rotation speed loop adjustment on the difference to obtain an adjustment amount, and accumulating the adjustment amounts to obtain a rotation speed loop control amount.

[0012] According to one embodiment of the present disclosure, the motor control method further includes the steps of: obtaining the time of constant rotational speed operation and the control amount of the power loop in the process of controlling the motor to operate at a constant rotational speed; and when it is determined that the time is lower than a time threshold and the control amount of the rotational speed loop is higher than the control amount of the power loop, controlling the motor to operate at a constant power.

[0013] According to one embodiment of the present disclosure, the motor control method further includes the step of controlling the motor to reduce its speed and operate or stop it when it is determined that the time is not below a time threshold.

[0014] According to one embodiment of the present disclosure, the time threshold is determined by at least one of the following: the motor temperature rise, the heat dissipation conditions, and the rotor load capacity.

[0015] According to one embodiment of the present disclosure, the control amount of the power loop is the ratio of the target power to the DC bus voltage.

[0016] To achieve the above objective, an embodiment of the second aspect of this application provides a computer-readable storage medium that stores a motor control program and, when the motor control program is executed by a processor, realizes the motor control method described above.

[0017] To achieve the above objective, an embodiment of a third aspect of this application provides a motor controller that includes a memory, a processor, and a motor control program stored in the memory and executable by the processor, and when the processor executes the motor control program, the motor controller realizes the above motor control method.

[0018] To achieve the above objectives, an embodiment of a fourth aspect of this disclosure provides a motor control device that includes an acquisition module used to acquire the feedback rotational speed of a motor, and a control module used to control the motor to operate at a constant rotational speed, which, in the process of controlling the motor to operate at a constant power, acquires a rotational speed loop control amount using a second rotational speed threshold greater than the first rotational speed threshold and the feedback rotational speed, and when it is determined that the feedback rotational speed is higher than the second rotational speed threshold, sets the second rotational speed threshold as a predetermined amount for the rotational speed loop and sets the rotational speed loop control amount as an initial control amount for the rotational speed loop. [Effects of the Invention]

[0019] According to the motor control device in the embodiments of the present disclosure, in the process of the control module controlling the motor to operate at a constant power, when it is determined that the feedback rotation speed of the motor is higher than the first rotation speed threshold, the rotation speed loop control amount is obtained based on the second rotation speed threshold and the feedback rotation speed, and when it is determined that the feedback rotation speed is higher than the second rotation speed threshold, the second rotation speed threshold is used as the fixed amount of the rotation speed loop, and the rotation speed loop control amount is used as the initial control amount of the rotation speed loop. By controlling the motor to operate at a constant rotation speed, it is possible not only to effectively avoid damage caused by the rotation speed of the motor being too high, but also to achieve a smooth switch from the constant power operation of the motor to the constant rotation speed operation.

[0020] Additional aspects and advantages of the present disclosure are partially shown in the following description, some will become apparent from the following description, or can be understood by implementing the present disclosure.

Brief Description of the Drawings

[0021] [Figure 1] It is a schematic flowchart of a motor control method according to an embodiment of the present disclosure. [Figure 2] It is a schematic structural diagram of a motor control system according to an embodiment of the present disclosure. [Figure 3] It is a schematic flowchart of a motor control method according to another embodiment of the present disclosure. [Figure 4] It is a schematic flowchart of a motor control method according to another embodiment of the present disclosure. [Figure 5] It is a schematic block diagram of a motor controller according to an embodiment of the present disclosure. [Figure 6] It is a schematic block diagram of a motor control device according to an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0022] The following will describe the embodiments of the present disclosure in detail. Examples of the embodiments are shown in the drawings, where throughout the drawings, the same or similar markings indicate the same or similar elements or elements having the same or similar functions. The embodiments described by referring to the following drawings are exemplary and are used only for the purpose of explaining the present disclosure and should not be construed as limiting the present disclosure.

[0023] Hereinafter, referring to the drawings, a motor control method, a computer-readable storage medium, a motor controller, and a motor control device provided in an embodiment of the present disclosure will be described.

[0024] FIG. 1 is a schematic flowchart of a motor control method according to an embodiment of the present disclosure. Referring to what is shown in FIG. 1, the motor control method may include the following steps.

[0025] Step S1, in the process of controlling the motor to operate at a constant power, obtain the feedback rotation speed of the motor.

[0026] Note that the constant power operation of the motor means that the output power during the operation process of the motor basically does not change, that is, the output power basically coincides with the target power, and the output torque of the motor decreases as the rotation speed of the motor increases.

[0027] In an embodiment of the present disclosure, in the process of controlling the motor to operate at a constant power, as shown in FIG. 2, the power loop of the motor control system is connected to the current loop. At this time, the power loop generates a control quantity based on the target power and can input the control quantity into the current loop. By performing subsequent control by the current loop, the constant power operation of the motor is realized.

[0028] In some embodiments, the control quantity of the power loop is the ratio of the target power to the DC bus voltage.

[0029] For example, when it is necessary to control a motor for constant power operation, a target power is obtained. This target power may be a power set by the user, or it may be power automatically generated based on the system's control demands; it is not specifically limited here. After obtaining the target power, it is input into the power loop, and at the same time, the DC bus voltage is detected by a voltage detection electrical circuit. As shown in Figure 2, the DC bus voltage is the voltage at the DC input terminal of the inverter, and this DC bus voltage is input into the power loop. The power loop then divides the target power by the DC bus voltage to obtain the ratio between the two. This ratio is the control amount of the power loop, i.e., the default current, and it is input into the current loop. The current loop then performs subsequent control based on the default current, thereby achieving constant power operation of the motor.

[0030] During constant power operation of the motor, the motor's feedback rotational speed is acquired in real time. Optionally, a position sensor can be installed inside the motor to detect the motor's feedback rotational speed, or a voltage detection circuit can be installed at the AC output terminal of the inverter shown in Figure 2 to detect the zero-crossing of the motor's back EMF, and the motor's feedback rotational speed can be estimated based on the zero-crossing of the back EMF.

[0031] In step S2, when it is determined that the feedback rotation speed is higher than the first rotation speed threshold, the rotation speed loop control amount is obtained using the second rotation speed threshold and the feedback rotation speed, where the second rotation speed threshold is greater than the first rotation speed threshold.

[0032] The first and second rotational speed thresholds can be set according to the specific performance parameters of the motor, and the second rotational speed threshold is also set as the target rotational speed when the motor is operating at a constant rotational speed.

[0033] For example, during constant power operation of a motor, when the motor load decreases due to the influence of operating conditions, the motor's feedback rotational speed increases, and when it reaches a certain height, for example, higher than the first rotational speed threshold, the motor is then controlled to continue constant power operation and enters the speed loop buffer. That is, the second rotational speed threshold and the feedback rotational speed are used as inputs to the speed loop. At this point, the speed loop obtains a rotational speed loop control variable based solely on the second rotational speed threshold and the feedback rotational speed, but the speed loop does not participate in the control of the motor.

[0034] In some embodiments, the step of obtaining a rotational speed loop control amount using a second rotational speed threshold and a feedback rotational speed includes the steps of obtaining the difference between the second rotational speed threshold and the feedback rotational speed, performing rotational speed loop adjustment on the difference to obtain an adjustment amount, and accumulating the adjustment amounts to obtain a rotational speed loop control amount.

[0035] For example, when the feedback rotational speed is higher than the first rotational speed threshold, the motor is continuously controlled to operate at constant power, while the speed loop performs calculations only and does not control. At this time, the speed loop obtains the rotational speed difference between the second rotational speed threshold and the feedback rotational speed, and performs PI (Proportional Integral) adjustment or PID (Proportion Integration Differential) adjustment on the rotational speed difference to obtain an adjustment amount. The obtained adjustment amounts are then accumulated to obtain the rotational speed loop control amount.

[0036] The speed loop may optionally include an incremental PI or PID regulator, but regardless of the type of regulator used, the final output control of the speed loop is full-range.

[0037] Let's take the example where the speed loop includes an expanding PID regulator. The output of the expanding PID regulator is shown in equation (1).

[0038] △u(k)=Kp×[e(k)-e(k-1)]+Ki×e(k)+Kd×[e(k)-2e(k-1)-e(k-2)] (1)

[0039] Here, △u(k) is the output of the variable-rate PID regulator at time k, Kp is the proportionality constant, Ki is the integral constant, Kd is the derivative constant, and e(k), e(k-1), and e(k-2) are the rotational speed difference values ​​between the second rotational speed threshold and the feedback rotational speed at times k, k-1, and k-2, respectively.

[0040] Since the speed loop outputs a total amount, the speed loop control amount is obtained by first acquiring the output amount △u(k) of the incremental PID regulator at time k, and then accumulating the output amounts △u(k) again.

[0041] Note that the speed loop may be a position-type PI or PID regulator, and since the output of an increment-type PI or PID regulator is a total-rate type, it is not necessary to accumulate the output adjustment amounts, and it is sufficient that the increment-type PI or PID regulator is in a calculation state. As an example, if the speed loop includes a position-type PID regulator, the output of the position-type PID regulator is shown in equation (2).

[0042] u(k)=Kp×e(k)+Ki×Σe(i)+Kd×[e(k)-e(k-2)], where i=0,...,k (2)

[0043] Here, u(k) is the output of the position-type PID regulator at time k, Kp is the proportionality constant, Ki is the integral constant, Kd is the derivative constant, e(k) and e(k-1) are the rotational speed difference between the second rotational speed threshold and the feedback rotational speed at time k and time k-1, respectively, and Σ indicates that the sum is calculated.

[0044] In step S3, when it is determined that the feedback rotational speed is higher than the second rotational speed threshold, the second rotational speed threshold is set as the default amount for the rotational speed loop, the control amount for the rotational speed loop is set as the initial control amount for the rotational speed loop, and the motor is controlled to operate at a constant rotational speed.

[0045] Constant rotational speed operation of a motor means that the feedback rotational speed during the motor's operation does not change fundamentally; that is, the feedback rotational speed basically matches the target rotational speed, and this target rotational speed is the second rotational speed threshold. In other words, when the motor's feedback rotational speed rises to the second rotational speed threshold, the motor is controlled to operate at a constant rotational speed, with the second rotational speed threshold being the target rotational speed. This prevents the motor's rotational speed from continuously increasing and reaching a considerably high rotational speed for an extended period, which could cause damage to the motor's rotor system.

[0046] For example, during constant power operation of the motor, when the feedback rotational speed is higher than the second rotational speed threshold, the connection between the power loop and the current loop of the motor control system is disconnected, and the rotational speed loop is connected to the current loop, so that the rotational speed loop begins to participate in the motor control. At the time when control begins, the rotational speed loop control amount obtained in step S2 is input to the current loop as the initial control amount of the speed loop, and subsequent control is performed by the current loop, thereby achieving a smooth transition from constant power operation to constant rotational speed operation of the motor. Then, the second rotational speed threshold is input to the speed loop as the target rotational speed, becoming the predetermined amount of the speed loop, and the motor is controlled to operate at a constant rotational speed. Here, when the motor is controlled to operate at a constant rotational speed, the speed loop obtains the rotational speed difference value between the second rotational speed threshold and the feedback rotational speed, performs PI adjustment or PID adjustment on the rotational speed difference value and outputs a control amount, and inputs the control amount to the current loop, and subsequent control is performed by the current loop, thereby achieving constant rotational speed control of the motor.

[0047] In the above embodiment, when the motor is controlled for constant power operation, if the motor's feedback rotational speed is higher than the first rotational speed threshold, the motor is controlled to continue constant power operation while simultaneously putting the speed loop into a continuous calculation state. When the feedback rotational speed is higher than the second rotational speed threshold, the calculation result is used as the initial control amount for the rotational speed loop, and the second rotational speed threshold is set to a predetermined amount. This controls the motor to operate at a constant rotational speed, effectively preventing damage caused by excessively high motor rotational speeds. Furthermore, it enables a smooth transition from constant power operation to constant rotational speed operation, improving the safety and reliability of motor operation.

[0048] Furthermore, referring to Figure 3, the above motor control method may further include the following steps.

[0049] In step S4, during the process of controlling the motor to operate at a constant rotational speed, the time of constant rotational speed operation and the amount of power loop control are acquired.

[0050] For example, when a motor is operated at a constant rotational speed, the timer records the time the motor is operating at that constant speed, while simultaneously acquiring the control amount of the power loop. That is, when the motor is operated at a constant rotational speed, the power loop is in a state where it only performs calculations and does not participate in control. At this time, the power loop calculates and acquires the control amount using the target power and DC bus voltage, specifically by dividing the target power by the DC bus voltage to acquire the control amount.

[0051] In step S5, when it is determined that the time is lower than the time threshold and the control amount of the rotation speed loop is higher than the control amount of the power loop, the motor is controlled to operate at constant power.

[0052] In other words, if the control amount of the rotational speed loop is higher than the control amount of the power loop within a short period of time, the motor load returns to normal. At this time, the connection between the rotational speed loop and the current loop of the motor control system is disconnected, and the power loop is connected to the current loop, thereby controlling the motor to operate at a constant power level.

[0053] In some selectable embodiments, the difference between the control amount of the rotational speed loop and the control amount of the power loop can be obtained. When the control amount of the rotational speed loop is higher than the control amount of the power loop, the difference is smaller than a preset threshold, and the time is lower than a time threshold, the motor is controlled to operate at constant power. Here, the difference can be set to a maximum value that does not cause shock during the switching of motor operation, thereby enabling a smooth transition of the motor from constant rotational speed operation to constant power operation.

[0054] The time threshold can be determined by the motor's performance parameters, such as one or more of the following: motor temperature rise, heat dissipation, and rotor load capacity.

[0055] In step S6, when it is determined that the time is not below the time threshold, the motor is controlled to reduce speed and operate or stop.

[0056] In other words, if the control amount of the rotational speed loop is lower than the control amount of the constant power loop over a long period of time, the motor load may not recover and may remain in a constant light load state. In this case, the motor can be controlled to reduce its speed or stop, thereby preventing the motor from remaining in a light load high-speed operation state for extended periods.

[0057] As one specific example, as shown in Figure 4, the motor control method may include the following steps.

[0058] Step S301: Control the motor to operate at a constant power level.

[0059] Step S302, obtain the motor's feedback rotational speed.

[0060] In step S303, determine whether the feedback rotation speed is higher than the first rotation speed threshold. If it is higher, perform step S304; otherwise, return to step S301.

[0061] In step S304, the rotation speed loop control amount is obtained using the second rotation speed threshold and the feedback rotation speed.

[0062] In step S305, determine whether the feedback rotational speed is higher than the second rotational speed threshold. If it is higher, perform step S306; otherwise, return to step S301.

[0063] Step S306: Control the motor to operate at a constant rotational speed.

[0064] In step S307, the time of constant rotational speed operation and the control amount of the power loop are obtained.

[0065] In step S308, determine whether the time of constant rotational speed operation is lower than a time threshold. If it is lower, perform step S309; ​​otherwise, perform step S311.

[0066] In step S309, determine whether the control amount of the rotational speed loop is higher than the control amount of the power loop. If it is higher, perform step S310; otherwise, return to step S306.

[0067] Step S310: The motor is controlled to operate at a constant power level.

[0068] Step S311: Control the motor to reduce its speed and operate it, or stop it.

[0069] From the above, according to the motor control method in the embodiment of this disclosure, in the process of controlling the motor to operate at a constant power, the motor's feedback rotational speed is obtained, and when the feedback rotational speed is higher than the first rotational speed threshold, a rotational speed loop control amount is obtained using the second rotational speed threshold and the feedback rotational speed, and when the feedback rotational speed is higher than the second rotational speed threshold, the second rotational speed threshold is set as the predetermined amount of the rotational speed loop, and the rotational speed loop control amount is set as the initial control amount of the rotational speed loop, thereby controlling the motor to operate at a constant rotational speed. This not only ensures the safety and reliability of the operation of the motor's rotor system after the rotational speed has suddenly increased due to the influence of factors such as extreme conditions when the motor is operated at a constant power, but also enables a smooth switch from constant power operation to constant rotational speed operation of the motor, reducing the impact of switching control methods.

[0070] In accordance with the embodiments described above, this disclosure further provides computer-readable storage media.

[0071] An embodiment of the present disclosure is a computer-readable storage medium that stores a motor control program therein, and when the motor control program is executed by a processor, the motor control method described above is realized.

[0072] According to the computer-readable storage medium in the embodiments of this disclosure, by implementing the motor control method described above, it is possible to effectively avoid damage caused by excessively high motor rotation speeds, as well as to achieve a smooth transition from constant power operation to constant rotation speed operation of the motor.

[0073] In accordance with the above embodiments, this disclosure further provides a motor controller.

[0074] Figure 5 is a schematic block diagram of a motor controller according to one embodiment of the present disclosure.

[0075] As shown in Figure 5, the motor controller 100 in the embodiment of this disclosure includes a memory 110, a processor 120, and a motor control program stored in the memory 110 and executable by the processor 120, and when the processor 120 executes the program, the motor control method described above is realized.

[0076] According to the motor controller in the embodiment of this disclosure, by implementing the above motor control method, it is possible to effectively avoid damage caused by excessively high motor rotation speeds, as well as to achieve a smooth transition from constant power operation to constant rotation speed operation of the motor.

[0077] In accordance with the above embodiments, this disclosure further provides a motor control device.

[0078] Figure 6 is a schematic block diagram of a motor control device according to one embodiment of the present disclosure.

[0079] As shown in Figure 6, the motor control device 200 in the embodiment of this disclosure may include an acquisition module 210 and a control module 220.

[0080] Here, the acquisition module 210 is used to acquire the motor's feedback rotational speed. The control module 220, in the process of controlling the motor for constant power operation, acquires a rotational speed loop control amount using the second rotational speed threshold and the feedback rotational speed when it is determined that the feedback rotational speed is higher than the first rotational speed threshold, and when it is determined that the feedback rotational speed is higher than the second rotational speed threshold, it sets the second rotational speed threshold as the default amount for the rotational speed loop and the rotational speed loop control amount as the initial control amount for the rotational speed loop, and is used to control the motor for constant rotational speed operation, where the second rotational speed threshold is greater than the first rotational speed threshold.

[0081] According to one embodiment of the present disclosure, the control module 220 acquires a rotation speed loop control amount using a second rotation speed threshold and a feedback rotation speed. Specifically, it is used to acquire the difference between the second rotation speed threshold and the feedback rotation speed, to perform rotation speed loop adjustment on the difference to obtain an adjustment amount, and to accumulate the adjustment amounts to obtain a rotation speed loop control amount.

[0082] According to one embodiment of the present disclosure, the control module 220 further utilizes the following in the process of controlling the motor to operate at a constant rotational speed: obtaining the time of constant rotational speed operation and the control amount of the power loop; and controlling the motor to operate at a constant power when it is determined that the time is lower than a time threshold and the control amount of the rotational speed loop is higher than the control amount of the power loop.

[0083] According to one embodiment of the present disclosure, the control module 220 is further used to control the motor to reduce its speed and operate or stop it when it is determined that the time is not below a time threshold.

[0084] According to one embodiment of the present disclosure, the time threshold is determined by at least one of the following: the motor temperature rise, the heat dissipation conditions, and the rotor load capacity.

[0085] According to one embodiment of the present disclosure, the control amount of the power loop is the ratio of the target power to the DC bus voltage.

[0086] Details not disclosed in the motor control device in the embodiments of this disclosure are omitted here, as they are not shown in the motor control method in the embodiments of this disclosure.

[0087] According to the motor control device in the embodiment of this disclosure, in the process of controlling the motor to operate at a constant power level, when the motor's feedback rotational speed is higher than a first rotational speed threshold, the control module obtains a rotational speed loop control amount using a second rotational speed threshold and the feedback rotational speed. Furthermore, when the feedback rotational speed is higher than the second rotational speed threshold, the second rotational speed threshold is set as the default amount for the rotational speed loop, and the rotational speed loop control amount is set as the initial control amount for the rotational speed loop. By controlling the motor to operate at a constant rotational speed, damage caused by excessively high motor rotational speed can be effectively avoided, and a smooth transition from constant power operation to constant rotational speed operation of the motor can also be achieved.

[0088] Furthermore, the logic and / or steps shown in the flowchart or otherwise described herein may be considered, for example, a command-executable sequence list for realizing a logical function and may be specifically implemented on any computer-readable medium for use in a command-execution system, apparatus or device (including, for example, a computer-based system, a processor system or a system that takes and executes commands from or in combination with such command-execution systems, apparatus or devices). For the purposes of this specification, “computer-readable medium” may include any command-execution system, apparatus or device or apparatus for combination with such command-execution systems, apparatus or devices that can contain, store, communicate, propagate or transmit any program. More specific examples of computer-readable mediums (a non-exclusive list) include electrical connections with one or more wires (electronic devices), portable computer disk enclosures (magnetic devices), random access memory (RAM), read-only memory (ROM), write-erase read-only memory (EPROM or flash memory), fiber optic devices, and portable CD-ROMs. Furthermore, the medium may be a computer-readable medium, or even paper or other suitable medium on which the program can be printed, because the program can be acquired electronically by, for example, optically scanning paper or other medium, and then editing, interpreting, or processing it in any other suitable way as needed, and then stored in computer memory.

[0089] Each part of this disclosure can be implemented in hardware, software, firmware, or a combination thereof. In the above implementation, multiple steps or methods can be implemented in software or firmware stored in memory and executed by an appropriate command execution system. For example, when implemented in hardware, it can be implemented in any one of the following, or a combination thereof, known in the art, such as discrete logic circuits having logic circuits for realizing logic functions in data signals, application-specific integrated circuits having appropriate combinational logic circuits, programmable gate arrays (PGAs), and field-programmable gate arrays (FPGAs), as in the other implementation.

[0090] In this specification, references to terms such as “one embodiment,” “several embodiments,” “example,” “specific example,” or “several examples” mean that the specific features, structures, materials, or properties described in that embodiment or example are included in at least one embodiment or example of this disclosure. In this specification, expressions used to indicate the meaning of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or properties described may be combined in appropriate ways in any one or more embodiments or examples.

[0091] Furthermore, the terms “first” and “second” are used solely for descriptive purposes and should not be understood as indicating or suggesting relative importance or specifying the number of technical features being referred to. For this reason, features designated as “first” or “second” may be explicitly or implicitly defined as including at least one such feature. In the description of this disclosure, “plural” means at least two unless otherwise explicitly and specifically defined, such as two, three, etc.

[0092] In this disclosure, unless otherwise expressly provided and limited, terms such as “attachment,” “connection,” “connection,” and “fixed” should be interpreted broadly, for example, and may include fixed connections, removable connections or integrations, mechanical connections or electrical connections, direct connections or indirect connections via a medium, internal communication between two parts, or the interaction relationship between two parts. A person skilled in the art will be able to understand the specific meaning of the above terms in this disclosure depending on the specific circumstances.

[0093] Although the above has already shown and described embodiments of the present disclosure, these embodiments are illustrative and cannot be interpreted as limiting the present disclosure, and those skilled in the art can modify, alter, substitute, and transform the above embodiments within the scope of the present disclosure.

Claims

1. The process involves controlling the motor to operate at a constant power level, and obtaining the feedback rotational speed detected by a position sensor installed inside the motor. If the feedback rotation speed is higher than the first rotation speed threshold, the step is to obtain a rotation speed loop control amount using a second rotation speed threshold that is higher than the first rotation speed threshold and the feedback rotation speed. The step includes: when the feedback rotation speed becomes higher than the second rotation speed threshold, setting the second rotation speed threshold as the default amount of the rotation speed loop, setting the rotation speed loop control amount at that time as the initial control amount of the rotation speed loop, and controlling the motor to operate at a constant rotation speed; A motor control method comprising: controlling the motor to continue constant power operation and continuing to acquire the rotation speed loop control amount when the feedback rotation speed is higher than the first rotation speed threshold and the feedback rotation speed does not exceed the second rotation speed threshold.

2. The step of obtaining a rotation speed loop control amount using the second rotation speed threshold and the feedback rotation speed is as follows: Obtaining the difference between the second rotational speed threshold and the feedback rotational speed, The adjustment amount is obtained by applying rotational speed loop adjustment to the aforementioned difference value, The motor control method according to claim 1, comprising accumulating the adjustment amounts to obtain the rotation speed loop control amount.

3. The process of controlling the motor to operate at a constant rotational speed includes the steps of obtaining the time of constant rotational speed operation and the control amount of the power loop, The motor control method according to claim 1 or 2, further comprising the step of controlling the motor to operate at constant power when it is determined that the time is lower than a time threshold and the control amount of the rotation speed loop is higher than the control amount of the power loop.

4. The motor control method according to claim 3, further comprising the step of controlling the motor to reduce its speed or stop it when it is determined that the aforementioned time is not lower than the aforementioned time threshold.

5. The motor control method according to claim 3, wherein the time threshold is determined by at least one of the motor temperature rise, heat dissipation conditions, and rotor load capacity.

6. The motor control method according to claim 3, wherein the control amount of the power loop is the ratio of the target power to the DC bus voltage.

7. A computer-readable storage medium that stores a motor control program and, when the motor control program is executed by a processor, realizes the motor control method described in any one of claims 1 to 6.

8. A motor controller comprising memory, a processor, and a motor control program stored in the memory and executable by the processor, wherein when the processor executes the motor control program, the motor controller realizes the motor control method described in any one of claims 1 to 6.

9. An acquisition module used to acquire the feedback rotational speed detected by a position sensor installed inside the motor, A motor control device comprising: a control module that, in the process of controlling a motor to operate at a constant power level, acquires a rotation speed loop control amount using a second rotation speed threshold higher than the first rotation speed threshold and the feedback rotation speed when the feedback rotation speed is higher than the second rotation speed threshold, sets the second rotation speed threshold as the default amount of the rotation speed loop, sets the rotation speed loop control amount at that point as the initial control amount of the rotation speed loop, and uses this to control the motor to operate at a constant rotation speed; and, when the feedback rotation speed is higher than the first rotation speed threshold and the feedback rotation speed does not exceed the second rotation speed threshold, continues to control the motor to operate at a constant power level and continues to acquire the rotation speed loop control amount.

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