Motor and control method, device, storage medium and computer program product thereof

Abstract

The application belongs to the technical field of electric machines, and discloses an electric machine and a control method, device, storage medium and computer program product thereof. The method comprises the following steps: in the case of needing to start the electric machine, obtaining the rotating speed of the electric machine and the output signal of a Hall position sensor unit; determining whether the electric machine is not started and in a downwind state according to the rotating speed of the electric machine and the output signal of the Hall position sensor unit; if it is determined that the electric machine is not started and in the downwind state, controlling the output voltage of an inverter unit to be a preset voltage, so that the electric machine starts to rotate; after a first set time, adjusting the output voltage of the inverter unit, so that the electric machine is started in the downwind state after speed reduction, and then runs after speed increase. According to the scheme, when the electric machine is started in the downwind state, the electric machine is first started in the downwind state after speed reduction to a minimum value, and then runs after speed increase to a target value after stabilization, so that the electric machine is started in the downwind state in silence and will not run with speed overshoot, and the reliability and use experience are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a control method and device of an electric machine, the electric machine, a storage medium and a computer program product, and especially relates to a control method and device suitable for adaptive starting and running of an electric machine in a downwind state. BACKGROUND

[0002] With the mature development of household appliance technology and the rapid advancement of power electronics technology, and the national energy efficiency upgrade, brushless DC motors are increasingly popular and widely used in the household appliance field due to their high efficiency and low noise. The working principle of an electric machine (such as a brushless DC motor) is to determine the rotor position through a Hall position sensor, thereby generating six PWM signals (i.e. pulse width modulation signals, which are a kind of square wave signals with a fixed period and adjustable width) to turn on or turn off the corresponding switching tubes in the electric machine control module (such as an IPM module (intelligent power module) or an inverter) to form a rotating magnetic field and drive the electric machine to run normally. However, if the electric machine is directly accelerated to run after hard starting with a large current in a downwind state, it is prone to produce starting noise and speed overshoot running problems.

[0003] The above content is only used to assist in understanding the technical solutions of the present application and does not represent an acknowledgement that the above content is prior art. SUMMARY

[0004] The purpose of the present application is to provide a control method and device of an electric machine, the electric machine, a storage medium and a computer program product, to solve the problem that the electric machine is prone to produce starting noise and speed overshoot running if it is directly accelerated to run after hard starting with a large current in a downwind state, so as to ensure that the electric machine is silently started and does not run with speed overshoot in a downwind state, and to improve reliability and user experience.

[0005] The present application provides a control method of an electric machine, the electric machine having a Hall position sensor unit, and a controller of the electric machine having an inverter unit; the control method of the electric machine comprises: in the case where the electric machine needs to be started, obtaining the speed of the electric machine and the output signal of the Hall position sensor unit; determining whether the electric machine is not started and is in a downwind state according to the speed of the electric machine and the output signal of the Hall position sensor unit; if it is determined that the electric machine is not started and is in a downwind state, controlling the output voltage of the inverter unit to be a preset voltage to make the electric machine rotate; after a first set time, adjusting the output voltage of the inverter unit to make the electric machine run after being started in a downwind state after being slowed down, and then making the electric machine run after being accelerated.

[0006] In some embodiments, determining whether the motor is not started and in the downwind state according to the rotation speed of the motor and the output signal of the Hall position sensor unit comprises: determining whether the motor is not started and in the downwind state according to whether the motor is not controlled to output PWM and the output signal of the Hall position sensor unit is the same as the preset output signal of the Hall position sensor unit when the motor is in the downwind state.

[0007] In some embodiments, the inverter unit has a switching tube module, and the output voltage of the inverter unit is controlled to be a preset voltage to make the motor start rotating, which comprises: outputting a PWM signal with a preset rotation duty cycle to the switching tube module of the inverter unit to make the output voltage of the inverter unit be the preset voltage and make the motor start rotating.

[0008] In some embodiments, the output voltage of the inverter unit is adjusted to make the motor start in the downwind state after speed reduction, and the motor is made to run at a high speed after starting in the downwind state, which comprises: limiting the output voltage of the inverter unit to reduce the rotation speed of the motor; until the rotation speed of the motor is reduced to a preset minimum rotation speed of the motor, the motor is controlled to start in the downwind state; after the motor starts in the downwind state for a second set time or after the motor starts in the downwind state to a set degree of stability, the output voltage of the inverter unit is increased to increase the rotation speed of the motor; until the rotation speed of the motor is increased to a target rotation speed of the motor, the motor is controlled to switch from the starting stage to the running stage and runs at the target rotation speed of the motor in the running stage.

[0009] In some embodiments, the inverter unit has a switching tube module, and the output voltage of the inverter unit is limited to reduce the rotation speed of the motor, which comprises: after outputting a PWM signal with a preset rotation duty cycle to the switching tube module of the inverter unit, the duty cycle of the PWM signal is reduced to reduce the output voltage of the inverter unit and reduce the rotation speed of the motor; until the duty cycle of the PWM signal is reduced to a preset minimum duty cycle, the rotation speed of the motor is reduced to a preset minimum rotation speed of the motor.

[0010] In some embodiments, the inverter unit has a switching tube module; increasing the output voltage of the inverter unit to increase the rotating speed of the motor comprises: after outputting a PWM signal with a preset minimum duty cycle to the switching tube module of the inverter unit, increasing the duty cycle of the PWM signal, increasing the output voltage of the inverter unit, and increasing the rotating speed of the motor; until the duty cycle of the PWM signal is increased to a target duty cycle, the rotating speed of the motor is increased to a target rotating speed of the motor.

[0011] In some embodiments, the control unit determines whether the motor is not started and in a tailwind state according to the rotating speed of the motor and the output signal of the Hall position sensor unit, which comprises: determining whether the motor is not started and in a tailwind state according to whether the motor is not controlled by a PWM signal and the output signal of the Hall position sensor unit is the same as a preset output signal of the Hall position sensor unit when the motor is in a tailwind state.

[0012] In some embodiments, the control unit determines whether the motor is not started and in a tailwind state according to the rotating speed of the motor and the output signal of the Hall position sensor unit, which comprises: determining whether the motor is not controlled by a PWM signal and the output signal of the Hall position sensor unit is the same as a preset output signal of the Hall position sensor unit when the motor is in a tailwind state.

[0013] In some embodiments, the inverter unit has a switching tube module; the control unit controls the output voltage of the inverter unit to be a preset voltage to start the motor, which comprises: outputting a PWM signal with a preset rotating duty cycle to the switching tube module of the inverter unit to control the output voltage of the inverter unit to be a preset voltage to start the motor.

[0014] In some embodiments, the control unit adjusts the output voltage of the inverter unit to reduce the speed of the motor, and then to start the motor in the wind, and then to increase the speed of the motor to run, including: limiting the output voltage of the inverter unit to reduce the speed of the motor; until the speed of the motor is reduced to the preset minimum speed of the motor, the motor is started in the wind; after the motor is started in the wind for a second set time, or after the motor is started in the wind to a set degree of stability, the output voltage of the inverter unit is increased to increase the speed of the motor; until the speed of the motor is increased to the target speed of the motor, the motor is switched from the starting stage to the running stage, and runs at the target speed of the motor in the running stage.

[0015] In some embodiments, the inverter unit has a switching tube module; the control unit limits the output voltage of the inverter unit to reduce the speed of the motor, including: after outputting a PWM signal with a preset rotation duty cycle to the switching tube module of the inverter unit, reducing the duty cycle of the PWM signal to reduce the output voltage of the inverter unit and reduce the speed of the motor; until the duty cycle of the PWM signal is reduced to the preset minimum duty cycle, the speed of the motor is reduced to the preset minimum speed of the motor.

[0016] In some embodiments, the inverter unit has a switching tube module; the control unit increases the output voltage of the inverter unit to increase the speed of the motor, including: after outputting a PWM signal with a preset minimum duty cycle to the switching tube module of the inverter unit, increasing the duty cycle of the PWM signal to increase the output voltage of the inverter unit and increase the speed of the motor; until the duty cycle of the PWM signal is increased to the target duty cycle, the speed of the motor is increased to the target speed of the motor.

[0017] In another aspect, the application provides a motor matched with the above device, including: the above-mentioned motor control device.

[0018] In another aspect, the application provides a storage medium matched with the above method, including a stored program, wherein when the program runs, the device where the storage medium is located executes the steps of the above-mentioned motor control method.

[0019] In another aspect, the application provides a computer program product matched with the above method, including a computer program, which, when executed by a processor, realizes the steps of the above-mentioned motor control method.

[0020] Therefore, in the case of starting the motor, if it is determined that the motor is not started and is in the windward state, the output voltage of the motor is limited in the windward state to reduce the starting speed of the motor (for example, the duty cycle of the PWM signal of the motor control module is reduced to reduce the starting speed of the motor by limiting the output voltage of the motor); until the starting speed of the motor is reduced to the minimum operating speed of the motor, the motor is controlled to start in the windward state; after the motor starts in the windward state and the change amount of the motor speed in the set range is within the set speed error range, the speed of the motor is increased to the set target speed (for example, the duty cycle of the PWM signal of the motor control module is increased to increase the speed of the motor to the set target speed), and the motor is controlled to switch from the starting stage to the operating stage; thereby, when the motor is started in the windward state, the speed is first reduced to the minimum value, then the motor is started in the windward state, and after the starting is stable, the speed is increased to the target value, so that the motor is started in the windward state in silence and will not run with speed overshoot, and the reliability and use experience are improved.

[0021] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the application.

[0022] The technical solutions of the present application will be described in detail below with the help of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Flowchart of an embodiment of the motor control method of the present application;

[0024] Figure 2 Flowchart of an embodiment of determining whether the motor is not started and in the windward state in the method of the present application;

[0025] Figure 3 Flowchart of an embodiment of adjusting the output voltage of the inverter unit in the method of the present application;

[0026] Figure 4 Flowchart of an embodiment of limiting the output voltage of the inverter unit in the method of the present application;

[0027] Figure 5 Flowchart of an embodiment of increasing the output voltage of the inverter unit in the method of the present application;

[0028] Figure 6 Structural schematic diagram of an embodiment of the motor control device of the present application;

[0029] Figure 7 Control waveform schematic diagram of the motor windward starting PWM signal;

[0030] Figure 8 Fig. 1 is a schematic diagram of an overall control flow of a control method suitable for adaptive starting and running of a motor in a downwind state;

[0031] Figure 9 Fig. 4 is a schematic diagram of high and low level outputs of six states of a three-phase Hall sensor when the motor rotates.

[0032] In the embodiments of the present application, the reference signs in the accompanying drawings are as follows:

[0033] 102 - acquisition unit; 104 - control unit. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] It is considered that if the motor is directly accelerated to run after hard starting with large current in the downwind state, the problems of starting noise and speed overshoot running are easily caused. Therefore, the switching control mode of starting and running needs to be paid attention to during the starting and accelerating running of the motor in the downwind state, so as to avoid the problems of starting noise and speed overshoot running caused by downwind hard starting with large current.

[0036] Therefore, the present application provides a control method of a motor, specifically a control method suitable for adaptive starting and running of a motor in a downwind state, which controls the motor to reliably and silently start and run in the downwind state, so as to avoid the problems of starting noise and speed overshoot running caused by direct downwind starting and running.

[0037] According to the embodiments of the present application, a control method of a motor is provided, as shown in Figure 1 Fig. 1 is a schematic diagram of an overall control flow of a control method suitable for adaptive starting and running of a motor in a downwind state; Figure 1 Fig. 1 is a schematic diagram of an overall control flow of a control method suitable for adaptive starting and running of a motor in a downwind state;

[0038] At step S110, if the motor needs to be started, the rotation speed of the motor is acquired, and the output signal of the Hall position sensor unit is acquired; that is, if the motor is not started, the output signal of the Hall position sensor unit is acquired. The motor needs to be started, for example, when a start instruction of the motor is received.

[0039] At step S120, whether the motor is not started and in a tailwind state is determined according to the rotation speed of the motor and the output signal of the Hall position sensor unit; that is, if the motor is not started, the output signal of the Hall position sensor unit determines whether the motor is in a tailwind state.

[0040] At step S130, if it is determined that the motor is not started and in a tailwind state, the output voltage of the inverter unit is controlled to be a preset voltage, so as to start the motor; the preset voltage is a voltage that can start the motor from 0 rotation speed. In the present application, the output voltage of the inverter unit is exemplarily controlled, and of course, the output current of the inverter unit can also be controlled. Of course, if it is determined that the motor is started, the motor is controlled to continue running (i.e., running in a preset running mode); if it is determined that the motor is in a headwind state, the motor is controlled to continue starting (i.e., starting in a preset starting mode).

[0041] At step S140, after the output voltage of the inverter unit is controlled to be the preset voltage for a first set time, that is, after the motor is started, the output voltage of the inverter unit is adjusted, so as to start the motor in a tailwind state after the motor is slowed down, and then run the motor after the motor is accelerated. That is, if it is determined that the motor is in a tailwind state, the output voltage of the inverter unit is controlled, so as to start the motor in a tailwind state after the rotation speed of the motor is slowed down, and then run the motor after the rotation speed of the motor is accelerated. The first set time is a time for the inverter unit to output the preset voltage, so as to start the rotor of the motor.

[0042] In order to solve the problems of noise and speed overshoot operation of the brushless direct current motor during direct large current wind starting operation in the wind state, the scheme of the motor in the wind state self-adaptive control scheme is provided, specifically, a control scheme suitable for the motor in the wind state self-adaptive starting and operation, the duty cycle output of the PWM signal for controlling the opening or closing of the corresponding switch tube in the motor control module such as the IPM module (intelligent power module) or the inverter is adjusted to adaptively adjust the motor speed, realize the adaptive wind smooth starting and operation after the speed reduction, and control the motor to start and operate reliably and quietly based on the wind state, so as to solve the problems of starting noise and speed overshoot operation of the motor in the wind state.

[0043] In some embodiments, the specific process of determining whether the motor is not started and in the wind state in step S120 according to the speed of the motor and the output signal of the Hall position sensor unit is described below.

[0044] The specific process of determining whether the motor is not started and in the wind state in step S120 is further described below with reference to the embodiment flowchart of the method of the motor in the wind state in the application shown in the accompanying drawings. Figure 2 The specific process of determining whether the motor is not started and in the wind state in step S120 is further described below with reference to the embodiment flowchart of the method of the motor in the wind state in the application shown in the accompanying drawings.

[0045] In step S210, it is determined whether the motor has no PWM control and the output signal of the Hall position sensor unit is the same as the preset output signal of the Hall position sensor unit when the motor is in the wind state.

[0046] In step S220, if it is determined that the motor has no PWM control and the output signal of the Hall position sensor unit is the same as the preset output signal of the Hall position sensor unit when the motor is in the wind state, it is determined that the motor is not started and in the wind state.

[0047] In the scheme of the application, according to the speed of the motor and the output signal of the Hall position sensor unit, it can be accurately determined whether the motor is not started and in the wind state, and based on the wind state control of the motor, the motor can be started and operated reliably and quietly in the wind state, and the problems of starting noise and speed overshoot operation caused by direct wind starting and operation are avoided.

[0048] In some embodiments, the inverter unit has a switching tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0049] The step S130 of controlling the output voltage of the inverter unit to be a preset voltage to make the motor start rotating includes: outputting a PWM signal with a preset rotation duty ratio to the switching tube module of the inverter unit, so that the output voltage of the inverter unit is the preset voltage, and the motor starts rotating; wherein the preset voltage is a voltage that can make the motor start rotating.

[0050] The method for controlling the motor to start and run adaptively in the wind state according to the scheme of the application, by adjusting the duty ratio output of the PWM signal, realizes the control strategy of limiting the voltage and reducing the speed of the motor before starting and running in the wind state, realizes the low-noise and silent starting and stable running of the motor in the wind state, and avoids the problems of starting noise and overrunning of the motor caused by the influence of the wind state.

[0051] In some embodiments, the specific process of adjusting the output voltage of the inverter unit to make the motor start in the wind state after reducing the speed and then make the motor run after increasing the speed after the motor starts in the wind state in the step S140 is described in the following exemplary description.

[0052] The method for controlling the motor to start and run adaptively in the wind state according to the scheme of the application, by adjusting the duty ratio output of the PWM signal, realizes the control strategy of limiting the voltage and reducing the speed of the motor before starting and running in the wind state, realizes the low-noise and silent starting and stable running of the motor in the wind state, and avoids the problems of starting noise and overrunning of the motor caused by the influence of the wind state. Figure 3 The method for controlling the motor to start and run adaptively in the wind state according to the scheme of the application, by adjusting the duty ratio output of the PWM signal, realizes the control strategy of limiting the voltage and reducing the speed of the motor before starting and running in the wind state, realizes the low-noise and silent starting and stable running of the motor in the wind state, and avoids the problems of starting noise and overrunning of the motor caused by the influence of the wind state.

[0053] The step S310 of limiting the output voltage of the inverter unit to reduce the speed of the motor.

[0054] The step S320 of controlling the motor to start in the wind state until the speed of the motor is reduced to the preset minimum speed of the motor, specifically controlling the motor to start adaptively in the wind state.

[0055] The step S330 of increasing the output voltage of the inverter unit to increase the speed of the motor after the motor starts in the wind state for a second set time or after the motor starts in the wind state to a set degree of stability; wherein the second set time is the time when the motor starts adaptively in the wind state and reaches the preset degree of stability.

[0056] The step S340 of controlling the motor to switch from the starting stage to the running stage after the speed of the motor is increased to the target speed of the motor, and running at the target speed of the motor in the running stage.

[0057] The commonly used brushless DC motor is started by a large current in a wind condition, which can cause noise and speed overshoot problems; and the scheme of the application adjusts the duty cycle output of the PWM signal for turning on or turning off the corresponding switch tube in the motor control module such as the IPM module (intelligent power module) or the inverter, to adaptively adjust the motor speed, realize self-adaptive smooth start and operation in the wind, and realize speed slow-down after speed slow-down. On the one hand, the motor can be started in a low-noise state in the wind, without starting noise; on the other hand, the motor can be started in a wind state without speed overshoot.

[0058] In some embodiments, the inverter unit has a switch tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0059] The specific process of limiting the output voltage of the inverter unit to reduce the speed of the motor in step S310 is described in the following example.

[0060] The following will be described in combination with Figure 4 The flowchart of an embodiment of the method of the application for limiting the output voltage of the inverter unit is further described in the following example, which further describes the specific process of limiting the output voltage of the inverter unit in step S310, including steps S410 to S420.

[0061] In step S410, after outputting the PWM signal with the preset rotation duty cycle to the switch tube module of the inverter unit, the duty cycle of the PWM signal is reduced to reduce the output voltage of the inverter unit and reduce the speed of the motor.

[0062] In step S420, until the duty cycle of the PWM signal is reduced to the preset minimum duty cycle, the speed of the motor is reduced to the preset minimum speed of the motor.

[0063] Figure 7 The control waveform diagram of the PWM signal for the motor wind start is a control waveform diagram of the PWM signal for the brushless DC motor wind start. See Figure 7In the example shown, in the wind state, the duty cycle of the PWM signal is reduced in stage a to limit the motor output voltage, thereby reducing the motor speed; in stage b, the motor speed is reduced to the minimum starting speed of the motor (i.e., the minimum operating speed of the motor). In stage a, the motor is controlled to operate at the minimum speed in the wind state by reducing the duty cycle of the PWM signal to limit the motor starting voltage, so that the motor starts at the minimum speed in stage b to adapt to the current wind state. The motor is controlled to operate at the minimum speed, the speed frequency is small, and the speed waveform feedbacks the minimum speed of the motor. The motor is not affected by external wind conditions and operates normally; the problem of noise caused by direct starting switching of the motor in the wind state is avoided; the main control chip (such as MCU) in the motor control module is responsible for calculating and outputting six PWM signals (such as PWM1 signal, PWM2 signal, PWM3 signal, PWM4 signal, PWM5 signal, and PWM6 signal) from the collected FG feedback signal data, to realize closed-loop reduction or increase of the duty cycle of the PWM signal (a periodic fixed-width adjustable square wave signal, i.e., a pulse width modulation signal), and the specific function is to drive the motor control module (such as IPM module (intelligent power module) or inverter (i.e., three-phase inverter module)) to output a voltage with variable frequency and voltage amplitude, thereby driving the motor to rotate and make the motor speed reach the corresponding set target speed. Among them, the closed-loop reduction or increase of the duty cycle of the PWM signal means that the main control chip MCU judges the wind speed of the motor according to the received Hall signal converted into speed, realizes accurate adjustment of the duty cycle of the PWM signal to control the motor to escape from the wind state, and forms a wind speed closed-loop control.

[0064] Figure 8 The whole control flow diagram of a control method suitable for the motor to adaptively start and run in the wind state is shown in the figure, which is a whole control flow diagram of the brushless direct current motor wind starting. As shown in Figure 8 The whole control flow diagram of the brushless direct current motor wind starting includes:

[0065] Step 1, the MCU chip is normally powered, no PWM signal is sent out, the motor is not controlled, that is, it is in the unstarted state; but it can be determined whether it is in a static or wind state according to the received Hall signal feedback. If it is determined that the motor is in the unstarted state and in the wind state, the duty cycle of the PWM signal is gradually reduced to reduce the motor starting speed by limiting the voltage, and then step 2 is performed. That is, in the wind state, the duty cycle of the PWM signal is reduced to limit the motor output voltage to reduce the speed. Among them, the speed of the motor is determined by the Hall feedback, and the duty cycle of the PWM signal is controlled by the MCU to reduce it. Unstarted means that the motor has no PWM control, but the MCU is normally powered, and the motor is in the wind state. After the Hall sensor senses, the corresponding speed is the wind speed, not 0 speed; the uncertain speed means that the corresponding wind speed is different, resulting in different wind speeds; for example, the wind speed is greater than the minimum set starting speed, and the PWM duty cycle of the motor needs to be gradually reduced to limit the motor output voltage, so that the controlled speed of the motor runs to the set minimum speed, avoiding the minimum speed starting to be uncontrollable and still affected by the external wind, resulting in speed overshoot and fluctuation.

[0066] Among them, the motor determines the rotor position through the Hall position sensor, and the order of the six signals output by the three Hall position sensors in the wind state and the wind state is different to determine whether the motor is in the wind state or the wind state. The rotor of the brushless DC motor is N / S permanent magnet alternately installed, and U / V / W three Hall sensors are close to the rotor side, and the arrangement between them is 120° apart. When the motor rotates, the three-phase Hall sensor outputs 6 states of high and low level (such as Figure 9 ); to determine the wind direction, the three Hall outputs 011→001→101→100→110→010 are converted to the chip, and the chip receives the Hall signal conversion to determine that the motor is in the wind direction; the three Hall outputs 010→110→100→101→001→011 are converted to the chip, and the chip receives the Hall signal to determine that the motor is in the wind direction, Figure 9 is a schematic diagram of the 6 states of high and low level output by the three-phase Hall sensor when the motor rotates.

[0067] Step 2, make the motor output voltage limit small to start at the minimum speed to adapt to the current wind state, and then perform step 3. That is, in phase b, the motor speed is reduced to the minimum starting speed of the motor.

[0068] The scheme of the application can realize the adaptive control of the motor speed by adjusting the duty cycle of the PWM signal output, so as to realize the adaptive wind smooth starting and running of the motor after the motor speed is slowly reduced in the wind state. On the one hand, the motor can be started at low speed in the wind state with limited voltage and without starting noise. On the other hand, the motor speed can be increased after starting in the wind state without speed overshoot.

[0069] In some embodiments, the inverter unit has a switching tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0070] The specific process of increasing the output voltage of the inverter unit to increase the speed of the motor in step S330 is described below with reference to the following exemplary description.

[0071] The specific process of increasing the output voltage of the inverter unit in the method of the application is described below with reference to the flowchart of an embodiment shown in Figure 5 The specific process of increasing the output voltage of the inverter unit in step S330 is described below with reference to the flowchart of an embodiment shown in

[0072] Step S510: After outputting the PWM signal with the preset minimum duty cycle to the switching tube module of the inverter unit, increasing the duty cycle of the PWM signal, increasing the output voltage of the inverter unit, and increasing the speed of the motor.

[0073] Step S520: Until the duty cycle of the PWM signal is increased to the target duty cycle, the speed of the motor is increased to the target speed of the motor.

[0074] As shown in Figure 8 The overall control flow of the brushless DC motor wind starting also includes:

[0075] Step 3: After the motor is started and stabilized, the duty cycle of the PWM signal is increased to increase the speed of the motor to the set target speed for normal operation. That is, in stage c, the motor is started at minimum speed in the wind state by increasing the duty cycle of the PWM signal, and reaches the target speed. The MCU converts the speed according to the Hall waveform feedback of the motor, and the speed is within the normal set range, so that it can be judged that the speed is stable after starting; the MCU judges that the current speed is less than the target speed set externally, and increases the duty cycle of the output six-way PWM signal to increase the speed of the motor.

[0076] Referring to Figure 7In the shown example, in stage a, the motor output voltage is limited by reducing the duty cycle of the PWM signal to reduce the motor speed in the wind; in stage b, the motor speed is reduced to the minimum starting speed of the motor (i.e. the minimum operating speed of the motor); in stage c, the motor is started at the minimum speed in the wind by increasing the duty cycle of the PWM signal to reach the target speed; the problem of noise and speed overshoot caused by direct starting of the motor in the wind is solved.

[0077] As shown in Figure 7 , waveform one (i.e. the speed feedback waveform) reflects the speed of the motor in terms of frequency, i.e. speed n = 60f (frequency) / P (number of motor poles), and waveform two (i.e. the PWM waveform) is the duty cycle of the single pulse width modulation signal of the motor control module such as IPM module (intelligent power module) or inverter, i.e. the duty cycle of the PWM signal, which turns on or off the corresponding switch tube in the motor control module such as IPM module (intelligent power module) or inverter to form a rotating magnetic chain to drive the motor to run normally. The duty cycle refers to the percentage of high level (or conduction time) in a pulse period. The speed calculation n = 60f / p, where f is the frequency value corresponding to the single Hall output waveform, and p is the number of motor poles. The chip can calculate the motor speed by receiving the Hall output frequency; the speed feedback waveform here is the waveform of single Hall induction output. In the PWM period duty cycle, the period duty cycle refers to the percentage of high level (or conduction time) in a pulse period.

[0078] Referring to Figure 7 and Figure 8The whole control process of the brushless DC motor starting in the wind can be divided into three stages, i.e., a stage, a b stage and a c stage. In the a stage, the motor is in the wind state, the motor connected with the wind wheel is affected by external wind or other factors, resulting in that the motor is not started, but is driven to rotate by the wind wheel, and the motor outputs a FG (Frequency Generator) rotating speed signal, i.e., the motor is in the wind state. Because the motor is actually applied to a wind wheel whole machine load, and the motor is affected by the external wind wheel, the motor is in the wind state. The rotating speed frequency and the FG rotating speed signal are both single Hall output signals, and the frequency is the frequency of the corresponding Hall output signal, which can be converted into the corresponding motor rotating speed after being collected by the chip. In the c stage, after the motor is adapted to start in the wind, the duty cycle of the PWM signal is increased, the rotating speed frequency of the motor is increased, and the rotating speed of the motor is increased to the set target rotating speed, so as to avoid the rotating speed of the motor being over-modulated in the wind state. The MCU is responsible for calculating and outputting six PWM signals such as PWM1 signal, PWM2 signal, PWM3 signal, PWM4 signal, PWM5 signal and PWM6 signal, to realize closed-loop adjustment of the duty cycle of the PWM signal, and the specific function is to drive the motor control module such as IPM module (Intelligent Power Module) or inverter (i.e., three-phase inverter module) to output a voltage with variable frequency and voltage amplitude, and then drive the motor to rotate, so that the rotating speed of the motor reaches the corresponding set target rotating speed. The closed-loop adjustment of the duty cycle of the PWM signal means that the main control chip MCU judges the wind rotating speed of the motor according to the received Hall signal converted into the rotating speed, realizes accurate adjustment of the duty cycle of the PWM signal to control the motor to escape from the wind state, and forms a wind rotating speed closed-loop control.

[0079] Finally, the motor starting in the wind state is adaptively controlled and runs through the three stages (i.e., a stage, a b stage and a c stage). In the a stage, the motor does not output the PWM signal to drive the motor to run, the motor is first judged to be in the wind state through the Hall signal, the MCU outputs a signal for adjusting the duty cycle of the PWM signal to limit the output frequency and voltage of the three-phase inverter module, so that the motor runs at the minimum starting voltage, and the starting noise is avoided; in the b stage, the minimum rotating speed is started to adapt to the current wind state, the motor is controlled, is not affected by the wind, and runs at the minimum target rotating speed, and is gradually stabilized; and in the c stage, the duty cycle of the PWM signal is adjusted to drive the three-phase inverter module to output a large voltage with variable frequency and amplitude, so as to control the rotating speed of the motor to rise to the target high rotating speed, realize the rotating speed gear switching after starting, and avoid the rotating speed over-modulation and overspeed phenomenon.

[0080] The technical scheme of the embodiment is adopted, in the case of needing to start the motor, if it is determined that the motor is not started and is in the downwind state, the output voltage of the motor is limited in the downwind state to reduce the starting speed of the motor (for example, the duty cycle of the PWM signal of the motor control module is reduced to reduce the starting speed of the motor by limiting the output voltage of the motor); until the starting speed of the motor is reduced to the minimum running speed of the motor, the motor is controlled to start in the downwind state; after the motor starts in the downwind state and the variation of the motor speed in the set range is within the set speed error range, the speed of the motor is increased to the set target speed (for example, the duty cycle of the PWM signal of the motor control module is increased to increase the speed of the motor to the set target speed), and the motor is controlled to switch from the starting stage to the running stage; thus, when the motor is started in the downwind state, the speed is first reduced to the minimum value, then the motor is started in the downwind state, and after the motor is started stably, the speed is increased to the target value, so that the motor is started silently in the downwind state and will not run with speed overshoot, and the reliability and use experience are improved.

[0081] According to the embodiments of the application, a control device of a motor corresponding to the control method of the motor is also provided. Referring to Figure 6 The device of the application is shown in the structural schematic diagram of an embodiment thereof. The motor has a Hall position sensor unit, and the controller of the motor has an inverter unit; the inverter unit of the motor is, for example, an IPM module or a three-phase inverter module; the Hall position sensor unit is, for example, three Hall position sensors, which are used to determine the rotor position of the motor. In the scheme of the application, as shown in Figure 6 The control device of the motor includes an acquisition unit 102 and a control unit 104.

[0082] The acquisition unit 102 is configured to acquire the speed of the motor and the output signal of the Hall position sensor unit in the case of needing to start the motor; that is, the acquisition unit 102 is also configured to acquire the output signal of the Hall position sensor unit in the case of not starting the motor. The case of needing to start the motor is, for example, the case of receiving the starting instruction of the motor. The specific functions and processes of the acquisition unit 102 are described in step S110.

[0083] The control unit 104 is configured to determine whether the motor is not started and is in the downwind state according to the speed of the motor and the output signal of the Hall position sensor unit; that is, the control unit 104 is also configured to determine whether the motor is in the downwind state according to the output signal of the Hall position sensor unit in the case of not starting the motor. The specific functions and processes of the control unit 104 are described in step S120.

[0084] The control unit 104 is further configured to control the output voltage of the inverter unit to be a preset voltage if it is determined that the motor has not started and is in the downwind state, so as to make the motor start rotating; wherein the preset voltage is a voltage that can make the motor start rotating from 0 rotating speed. In the scheme of the application, the output voltage of the inverter unit is exemplarily described, and of course, the output current of the inverter unit can also be controlled. Of course, the control unit 104 is further configured to control the motor to continue running (i.e., running in a preset running mode) if it is determined that the motor has started, and control the motor to continue starting (i.e., starting in a preset starting mode) if it is determined that the motor is in the upwind state. The specific functions and processes of the control unit 104 are also described with reference to step S130.

[0085] After controlling the output voltage of the inverter unit to be the preset voltage for a first set time, i.e., after making the motor start rotating, the output voltage of the inverter unit is adjusted to make the motor start in the downwind state after speed reduction, and the motor is made to run after speed increase after the motor starts in the downwind state. That is, in the case where the motor has not started, if it is determined that the motor is in the downwind state, the output voltage of the inverter unit is controlled to make the rotating speed of the motor decrease, and then the motor is started in the downwind state, and the rotating speed of the motor is increased after the motor is started in the downwind state. The first set time is the time for the inverter unit to output the preset voltage to make the rotor of the motor start rotating. The specific functions and processes of the control unit 104 are also described with reference to step S140.

[0086] In order to solve the problems of noise and rotating speed overshoot running of the brushless direct current motor in the downwind state, the scheme of the application provides a control scheme for adaptive starting and running of the motor in the downwind state. The duty cycle output of the PWM signal for controlling the opening or closing of the corresponding switch tube in the motor control module such as the IPM module (intelligent power module) or the inverter is adjusted to adaptively adjust the rotating speed of the motor, realize adaptive downwind smooth starting and running after speed reduction, and control the motor to reliably and silently start and run based on the downwind state, so as to solve the problems of starting noise and rotating speed overshoot running of the motor in the downwind state.

[0087] In some embodiments, the control unit 104 determines whether the motor has not started and is in the downwind state according to the rotating speed of the motor and the output signal of the Hall position sensor unit, comprising:

[0088] The control unit 104 is further configured to determine whether the motor is not started and in the downwind state according to the motor speed and the output signal of the Hall position sensor unit.

[0089] The control unit 104 is further configured to determine that the motor is not started and in the downwind state if it is determined that the motor is not started and in the downwind state according to the motor speed and the output signal of the Hall position sensor unit.

[0090] In the scheme of the application, according to the motor speed and the output signal of the Hall position sensor unit, it can be accurately determined whether the motor is not started and in the downwind state, and based on the downwind state control, the motor can be reliably started and run in silence, so that the brushless DC motor can be reliably started and run in silence in the downwind state, and the problem of starting noise and speed overshoot running caused by direct downwind starting and running is avoided.

[0091] In some embodiments, the inverter unit has a switch tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0092] The control unit 104 controls the output voltage of the inverter unit to be a preset voltage to start the motor, including:

[0093] The control unit 104 is further configured to output a PWM signal with a preset rotation duty cycle to the switch tube module of the inverter unit, so that the output voltage of the inverter unit is a preset voltage, and the motor starts to rotate; wherein the preset voltage is a voltage that can make the motor start to rotate.

[0094] The scheme of the application proposes a control method for the motor to start and run in the downwind state, which adjusts the duty cycle output of the PWM signal to realize the control strategy of limiting the voltage and reducing the speed of the motor before starting and running in the downwind state, realizes the low-noise silent starting and stable running of the motor in the downwind state, and avoids the problem of starting noise and overshoot running of the motor caused by the downwind state.

[0095] In some embodiments, the control unit 104 adjusts the output voltage of the inverter unit to make the motor start in the downwind state after speed reduction, and then makes the motor run after speed increase after the motor starts in the downwind state, including:

[0096] The control unit 104 is further configured to limit the output voltage of the inverter unit to reduce the rotation speed of the motor. The specific functions and processes of the control unit 104 are also described in step S310.

[0097] The control unit 104 is further configured to control the motor to start in the wind condition until the rotation speed of the motor is reduced to the preset minimum rotation speed of the motor, and specifically to control the motor to start adaptively in the wind condition. The specific functions and processes of the control unit 104 are also described in step S320.

[0098] The control unit 104 is further configured to increase the output voltage of the inverter unit to increase the rotation speed of the motor after the motor starts in the wind condition for a second set time, or after the motor starts in the wind condition to a set degree of stability. The second set time is the time when the motor starts adaptively in the wind condition and reaches the preset degree of stability. The specific functions and processes of the control unit 104 are also described in step S330.

[0099] The control unit 104 is further configured to control the motor to switch from the starting stage to the running stage after the rotation speed of the motor is increased to the target rotation speed of the motor, and to run at the target rotation speed of the motor in the running stage. The specific functions and processes of the control unit 104 are also described in step S340.

[0100] The commonly used brushless DC motor is started by a large current in the wind condition, which may cause noise and rotation speed overshoot. The scheme of the present application adjusts the duty cycle output of the PWM signal for controlling the opening or closing of the corresponding switch tube in the motor control module such as the IPM module (intelligent power module) or the inverter, to adaptively adjust the motor speed, realize adaptive wind smooth starting and running after speed reduction, on the one hand, it can ensure the low noise starting of the motor in the wind condition, and on the other hand, it can ensure that there is no rotation speed overshoot after the motor starts in the wind condition.

[0101] In some embodiments, the inverter unit has a switch tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0102] The control unit 104 limits the output voltage of the inverter unit to reduce the rotation speed of the motor, comprising:

[0103] The control unit 104 is specifically further configured to reduce the duty cycle of the PWM signal after outputting the PWM signal with the preset rotation duty cycle to the switch tube module of the inverter unit, so as to reduce the output voltage of the inverter unit and reduce the rotation speed of the motor. For specific functions and processes of the control unit 104, please refer to step S410.

[0104] The control unit 104 is specifically further configured to reduce the rotation speed of the motor until the duty cycle of the PWM signal is reduced to a preset minimum duty cycle, and the rotation speed of the motor is reduced to a preset minimum rotation speed of the motor. For specific functions and processes of the control unit 104, please refer to step S420.

[0105] Figure 7 The control waveform diagram of the PWM signal for the motor to start in the wind is specifically the control waveform diagram of the PWM signal for the brushless direct current motor to start in the wind. Please refer to Figure 7 In the example shown, the duty cycle of the PWM signal is reduced in the a stage in the wind state to limit the motor output voltage and reduce the motor rotation speed; the b stage is that the motor rotation speed is reduced to the minimum starting rotation speed of the motor (i.e. the minimum running rotation speed of the motor). In the a stage in the wind state, the motor limits the motor starting running voltage by reducing the duty cycle of the PWM signal, so that the motor starts in the b stage with the minimum rotation speed to adapt to the current wind state, the motor is controlled to run at the minimum rotation speed, the rotation speed frequency is small, and the rotation speed waveform feedbacks the minimum rotation speed of the motor running, the motor is not affected by the external wind condition, and normally runs; the problem of noise generated by direct starting switching of the motor in the wind state is avoided; the main control chip (such as MCU) in the motor control module is responsible for calculating and outputting six PWM signals (such as PWM1 signal, PWM2 signal, PWM3 signal, PWM4 signal, PWM5 signal, and PWM6 signal) of the FG feedback signal data collected, so as to realize the closed loop reduction or increase of the duty cycle of the PWM signal (a kind of fixed period, adjustable width square wave signal, i.e. pulse width modulation signal), and the specific function is to drive the motor control module (such as IPM module (intelligent power module) or inverter (i.e. three-phase inverter module)) to output the voltage with variable frequency and voltage amplitude, and then drive the motor to rotate, so that the motor rotation speed reaches the corresponding set target rotation speed.

[0106] Figure 8 The whole control flow diagram of the control method suitable for the motor to start and run in the wind state is specifically the whole control flow diagram of the brushless direct current motor to start in the wind. As shown in Figure 8 The whole control flow of the brushless direct current motor to start in the wind includes:

[0107] Step 1, if the motor is determined to be in a non-starting state and in a wind state, the duty cycle of the PWM signal is gradually reduced to reduce the motor starting speed by limiting the voltage, and then step 2 is performed. That is, in the wind state, the a stage reduces the speed by reducing the duty cycle of the PWM signal to limit the motor output voltage. Among them, the motor judges the rotor position through the Hall position sensor, and the six signal sequence states output by the three Hall position sensors in the wind state and the wind state are different, to determine whether the motor is in the wind state or the wind state.

[0108] Step 2, after the motor output voltage is limited, the motor is started at the minimum speed to adapt to the current wind state, and then step 3 is performed. That is, the b stage reduces the motor speed to the minimum starting speed of the motor.

[0109] The scheme of the present application is that the motor is started in the wind state, the voltage is limited to reduce the speed, the duty cycle of the PWM is adjusted, the motor is started in the wind state with limited voltage and low speed, and there is no starting noise; After starting, the speed gear is switched up, and there is no speed overshoot and over speed phenomenon. Therefore, the scheme of the present application adjusts the duty cycle output of the PWM signal to adaptively control the motor speed, and realizes the adaptive wind smooth starting and running after the motor speed is reduced in the wind state; On the one hand, it can ensure that the motor is started in the wind state with limited voltage and low speed, and there is no starting noise; On the other hand, it can ensure that the motor speed rises after starting in the wind state, and there is no speed overshoot phenomenon.

[0110] In some embodiments, the inverter unit has a switch tube module, such as six IGBT tubes in a three-phase inverter bridge.

[0111] The control unit 104 increases the output voltage of the inverter unit to increase the speed of the motor, comprising:

[0112] The control unit 104 is specifically configured to increase the duty cycle of the PWM signal, increase the output voltage of the inverter unit, and increase the speed of the motor after outputting the PWM signal with the preset minimum duty cycle to the switch tube module of the inverter unit. The specific functions and processes of the control unit 104 are also referred to step S510.

[0113] The control unit 104 is specifically configured to increase the speed of the motor to the target speed of the motor until the duty cycle of the PWM signal increases to the target duty cycle. The specific functions and processes of the control unit 104 are also referred to step S520.

[0114] As Figure 8 shown, the overall control process of the brushless DC motor starting in the wind state also includes:

[0115] Step 3, after the motor starts to stabilize, increase the duty cycle of the PWM signal, so that the motor speed rises to the set target speed to run normally. That is, the c stage increases the duty cycle of the PWM signal to make the motor start at the minimum speed, and reaches the target speed.

[0116] Referring to Figure 7 In the example shown, the a stage reduces the duty cycle of the PWM signal to limit the motor output voltage to reduce the motor speed; the b stage reduces the motor speed to the minimum starting speed of the motor (i.e. the minimum running speed of the motor); the c stage increases the duty cycle of the PWM signal to make the motor start at the minimum speed, and reaches the target speed; solves the problem of noise and speed overshoot during motor starting in the wind state.

[0117] As Figure 7 shown, waveform one (i.e. speed feedback waveform) reflects the speed of the motor in frequency, i.e. speed n = 60f (frequency) / P (motor pole pairs), waveform two (i.e. PWM waveform) is the duty cycle of the single pulse width modulation signal of the motor control module such as IPM module (intelligent power module) or inverter, i.e. the duty cycle of the PWM signal, which turns on or off the corresponding switch tube in the motor control module such as IPM module (intelligent power module) or inverter to form a rotating magnetic chain to drive the motor to run normally. The duty cycle refers to the percentage of high level (or on time) in a pulse period.

[0118] Referring to Figure 7 and Figure 8 shown, the overall control process of the brushless DC motor starting in the wind can be divided into three stages, i.e. a stage, b stage and c stage. Among them, the a stage is when the motor is in the wind state, the motor connected to the wind wheel is affected by external wind or other factors, resulting in the motor not starting, but being driven by the wind wheel to rotate, the motor outputs the FG speed signal (Frequency Generator, frequency signal), i.e. the motor is in the wind state. The c stage increases the duty cycle of the PWM signal after the motor adapts to the wind start, the motor speed frequency becomes larger, so that the motor speed rises to the set target speed, avoiding the motor speed overshoot in the wind state. The MCU is responsible for calculating and outputting six PWM signals such as PWM1 signal, PWM2 signal, PWM3 signal, PWM4 signal, PWM5 signal and PWM6 signal from the collected FG feedback signal data, to realize the closed loop reduction or increase of the duty cycle of the PWM signal (a fixed period, adjustable width square wave signal, i.e. pulse width modulation signal), which specifically drives the motor control module such as IPM module (intelligent power module) or inverter (i.e. three-phase inverter module) to output a voltage with variable frequency and voltage amplitude to drive the motor to rotate, so that the motor speed reaches the corresponding set target speed.

[0119] Finally, the motor is self-adaptively started and run in the wind state through three stages, i.e., a stage, b stage and c stage. In the a stage, the motor is run without PWM signal, the motor is first determined to be in the wind state through the Hall signal, and the MCU sends a duty cycle signal of a reduced PWM signal to limit the output frequency and voltage of the three-phase inverter module, so that the motor is run at a minimum starting voltage to avoid starting noise; in the b stage, the motor is started at a minimum speed to adapt to the current wind state, the motor is controlled and is not affected by the wind, and is run at a minimum target speed to gradually stabilize; and in the c stage, the duty cycle signal of the PWM signal is adjusted to drive the three-phase inverter module to output a variable voltage with variable frequency, so that the motor speed is controlled to rise to a target high speed, the speed gear is switched after starting, and there is no speed overshoot and over-speed phenomenon.

[0120] Since the processing and functions realized by the device of the embodiment are basically corresponding to the foregoing embodiments, principles and examples of the method, the description of the embodiment is not described in detail, and the related description in the foregoing embodiments can be referred to, and will not be described here.

[0121] According to the embodiment of the application, a motor corresponding to the motor control device is also provided. The motor can include the motor control device described above.

[0122] Since the processing and functions realized by the motor of the embodiment are basically corresponding to the foregoing embodiments, principles and examples of the device, the description of the embodiment is not described in detail, and the related description in the foregoing embodiments can be referred to, and will not be described here.

[0123] According to the embodiment of the application, a computer program product corresponding to the motor control method is also provided, including a computer program, which, when executed by a processor, realizes the steps of the motor control method described above.

[0124] Since the processing and functions realized by the product of the embodiment are basically corresponding to the foregoing embodiments, principles and examples of the method, the description of the embodiment is not described in detail, and the related description in the foregoing embodiments can be referred to, and will not be described here.

[0125] According to the embodiment of the application, a storage medium corresponding to the motor control method is also provided, including a stored program, wherein when the program is running, the device where the storage medium is located executes the steps of the motor control method described above.

[0126] Since the processing and functions realized by the storage medium of the embodiment are basically corresponding to the foregoing embodiments, principles and examples of the method, the description of the embodiment is not described in detail, and the related description in the foregoing embodiments can be referred to, and will not be described here.

[0127] In summary, the person skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0128] The above merely provides an example of the present application, but is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of claims of the present application.

Claims

1. A method for controlling an electric motor, characterized in that, The motor has a Hall position sensor unit, and the motor controller has an inverter unit; the motor control method includes: When it is necessary to start the motor, the rotational speed of the motor is obtained, and the output signal of the Hall position sensor unit is obtained; Based on the motor's rotational speed and the output signal of the Hall position sensor unit, it is determined whether the motor is not started and is in a downwind state; If it is determined that the motor is not started and is in a downwind state, the output voltage of the inverter unit is controlled to a preset voltage to make the motor rotate. After a first set time, the output voltage of the inverter unit is limited to reduce the speed of the motor; until the speed of the motor is reduced to the preset minimum speed of the motor, the motor is controlled to start in a tailwind state; after the motor starts in a tailwind state for a second set time, or after the stability of the motor starting in a tailwind state reaches a set level, the output voltage of the inverter unit is increased to increase the speed of the motor; until the speed of the motor increases to the target speed of the motor, the motor is controlled to switch from the starting stage to the running stage, and runs at the target speed of the motor in the running stage.

2. The motor control method according to claim 1, characterized in that, Determining whether the motor is not running and is in a downwind state based on the motor's rotational speed and the output signal of the Hall position sensor unit includes: Determine whether the following conditions are met: the motor does not emit PWM control, and the output signal of the Hall position sensor unit is the same as the preset output signal of the Hall position sensor unit when the motor is in a downwind state; If it is determined that the motor does not emit PWM control and the output signal of the Hall position sensor unit is the same as the preset output signal of the Hall position sensor unit when the motor is in a downwind state, then it is determined that the motor is not started and is in a downwind state.

3. The motor control method according to claim 1, characterized in that, The inverter unit has a switching transistor module; Controlling the output voltage of the inverter unit to a preset voltage to make the motor rotate includes: A PWM signal with a preset rotation duty cycle is output to the switching transistor module of the inverter unit so that the output voltage of the inverter unit is the preset voltage, thereby causing the motor to rotate.

4. The motor control method according to claim 1, characterized in that, The inverter unit has a switching transistor module; Limiting the output voltage of the inverter unit to reduce the speed of the motor includes: After outputting a PWM signal with a preset rotation duty cycle to the switching transistor module of the inverter unit, the duty cycle of the PWM signal is reduced to reduce the output voltage of the inverter unit and reduce the speed of the motor. The motor speed will decrease to the preset minimum speed when the duty cycle of the PWM signal decreases to the preset minimum duty cycle.

5. The motor control method according to claim 1, characterized in that, The inverter unit has a switching transistor module; Increasing the output voltage of the inverter unit to increase the speed of the motor includes: After outputting a PWM signal with a preset minimum duty cycle to the switching transistor module of the inverter unit, the duty cycle of the PWM signal is increased, the output voltage of the inverter unit is increased, and the speed of the motor is increased. The motor speed increases to the target speed only when the duty cycle of the PWM signal increases to the target duty cycle.

6. A control device for an electric motor, characterized in that, The motor has a Hall position sensor unit, and the motor controller has an inverter unit; the motor control device includes: The acquisition unit is configured to acquire the rotational speed of the motor and the output signal of the Hall position sensor unit when the motor needs to be started. The control unit is configured to determine whether the motor is not started and is in a downwind state based on the motor speed and the output signal of the Hall position sensor unit; The control unit is also configured to, if it is determined that the motor is not started and is in a downwind state, control the output voltage of the inverter unit to a preset voltage so that the motor can rotate. After a first set time, the output voltage of the inverter unit is limited to reduce the speed of the motor; until the speed of the motor is reduced to the preset minimum speed of the motor, the motor is controlled to start in a tailwind state; after the motor starts in a tailwind state for a second set time, or after the stability of the motor starting in a tailwind state reaches a set level, the output voltage of the inverter unit is increased to increase the speed of the motor; until the speed of the motor increases to the target speed of the motor, the motor is controlled to switch from the starting stage to the running stage, and runs at the target speed of the motor in the running stage.

7. An electric motor, characterized in that, include: The motor control device as described in claim 6.

8. A storage medium, characterized in that, The storage medium includes a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the motor control method according to any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the motor control method according to any one of claims 1 to 5.

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