CN116827171A

CN116827171A - Motor starting control method and device, motor and storage medium

Info

Publication number: CN116827171A
Application number: CN202310516106.6A
Authority: CN
Inventors: 卢宝平; 姜睿; 吴文贤; 敖文彬; 周刘远; 林乃劲
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2023-05-09
Filing date: 2023-05-09
Publication date: 2023-09-29

Abstract

The invention discloses a motor starting control method, a motor starting control device, a motor and a storage medium, wherein the method comprises the following steps: when the motor needs to be started, determining a target torque according to a target rotating speed of the motor, and determining a voltage interval of a bus voltage of the motor; according to the voltage interval of the bus voltage, the duty ratio of the PWM signal of the exciting voltage of the motor is regulated, and the output of the PWM signal of the exciting voltage of the motor is controlled according to the regulated duty ratio, so that the torque output by the motor when the motor reaches the target rotating speed of the motor is the target torque of the motor, and when the voltage interval of the bus voltage of the motor is more than two different voltage intervals, the difference value between the time when the motor reaches the target rotating speed of the motor, namely the starting time difference value, is within the set error range. According to the scheme, the duty ratio of the PWM signals of the exciting voltage in the starting process of the motor is adjusted according to different starting voltages of the motor, so that the difference of starting time is reduced, and the user experience is improved.

Description

Motor starting control method and device, motor and storage medium

Technical Field

The invention belongs to the technical field of motors, and particularly relates to a motor starting control method, a motor starting control device, a motor and a storage medium, in particular to a high-speed motor constant torque starting control method, a high-speed motor constant torque starting control device, a motor and a storage medium.

Background

In the starting process of the motor, the larger the exciting voltage of the motor is, the faster the rotating speed of the motor is, and accordingly the larger the torque output by the motor is. In the starting process of the motor, the initial starting torque of the motor is different due to different starting voltages. Under the condition that the same gear signal is given to be electrified, the starting time of the motor reaching the preset gear rotating speed when the motor is started at low voltage is longer than the starting time of the motor reaching the preset gear rotating speed when the motor is started at higher voltage, and the use experience of a user is greatly influenced.

The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.

Disclosure of Invention

The invention aims to provide a starting control method, a device, a motor and a storage medium of a motor, so as to solve the problem that the starting time of the motor reaching a preset gear rotating speed when the motor is started at a low voltage is longer than the starting time of the motor reaching the preset gear rotating speed when the motor is started at a higher voltage under the condition that the same gear signal is electrified, greatly influence the use experience of a user, and achieve the effects of reducing the difference of the starting time of the motor under different starting voltages and being beneficial to improving the user experience by adjusting the duty ratio of PWM signals of exciting voltage in the starting process of the motor according to different starting voltages of the motor.

The invention provides a starting control method of a motor, which comprises the following steps: under the condition that the motor needs to be started, acquiring a target rotating speed of the motor and acquiring a bus voltage of the motor; the target rotating speed of the motor is the rotating speed when the motor is started; determining the torque required to be output by the motor when the target rotating speed of the motor is reached according to the target rotating speed of the motor, and recording the torque as the target torque of the motor; determining a section where the bus voltage of the motor is located in the range of the preset voltage section based on the range of the preset voltage section, and recording the section as a voltage section of the bus voltage of the motor; the range of the preset voltage interval includes: more than one voltage interval; according to the voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor; controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor so that the torque actually output by the motor when the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

In some embodiments, determining a torque that the motor needs to output if the motor reaches a target rotational speed of the motor, denoted as a target torque of the motor, according to the target rotational speed of the motor, includes: when the load of the motor is fixed, determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the load, and recording the torque as the target torque of the motor; and when the load of the motor changes, adjusting the target rotating speed of the motor according to the new load of the motor, and determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the new load, and recording the torque as the target torque of the motor.

In some embodiments, two or more different voltage intervals of the one or more voltage intervals comprise: a first voltage interval and a second voltage interval; the voltage amplitude of the first voltage interval is higher than that of the second voltage interval; according to the voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, and the method comprises the following steps: if the voltage interval of the bus voltage of the motor is the first voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, and the first duty ratio of the PWM signal of the exciting voltage of the motor is obtained and is used as the current duty ratio of the PWM signal of the exciting voltage of the motor; if the voltage interval of the bus voltage of the motor is the second voltage interval, increasing the duty ratio of the PWM signal of the exciting voltage of the motor to obtain the second duty ratio of the PWM signal of the exciting voltage of the motor, and taking the second duty ratio as the current duty ratio of the PWM signal of the exciting voltage of the motor; wherein the second duty cycle of the PWM signal of the excitation voltage of the motor is greater than the first duty cycle of the PWM signal of the excitation voltage of the motor.

In some embodiments, in a case where a voltage interval of a bus voltage of the motor is the first voltage interval, an excitation voltage of the motor is noted as a first excitation voltage of the motor; when the voltage interval of the bus voltage of the motor is the second voltage interval, the exciting voltage of the motor is recorded as the second exciting voltage of the motor; wherein the product of the amplitude of the first exciting voltage of the motor and the first duty ratio of the PWM signal of the exciting voltage of the motor is equal to the product of the amplitude of the second exciting voltage of the motor and the second duty ratio of the PWM signal of the exciting voltage of the motor.

In some embodiments, further comprising: determining whether the variation of the bus voltage of the motor exceeds a set voltage variation range or not in the process of controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor; if the change amount of the bus voltage of the motor is determined to be beyond the set voltage change range, re-determining the range of the bus voltage of the motor in the range of the preset voltage range based on the range of the preset voltage range, and recording the range as a new voltage range of the bus voltage of the motor; according to the new voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the new motor; controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the new motor so that the torque actually output by the motor under the condition that the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

In accordance with the above method, another aspect of the present invention provides a start control device for an electric motor, including: an acquisition unit configured to acquire a target rotation speed of the motor and acquire a bus voltage of the motor in a case where the motor needs to be started; the target rotating speed of the motor is the rotating speed when the motor is started; a control unit configured to determine, based on a target rotational speed of the motor, a torque that the motor needs to output when reaching the target rotational speed of the motor, and to record as a target torque of the motor; the control unit is further configured to determine, based on a range of preset voltage ranges, a range in which a bus voltage of the motor is located in the range of the preset voltage ranges, and record the range as a voltage range of the bus voltage of the motor; the range of the preset voltage interval includes: more than one voltage interval; the control unit is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor; the control unit is further configured to control output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor, so that torque actually output by the motor when the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

In some embodiments, the control unit determines, according to a target rotation speed of the motor, a torque that the motor needs to output if the target rotation speed of the motor is reached, denoted as a target torque of the motor, including: when the load of the motor is fixed, determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the load, and recording the torque as the target torque of the motor; and when the load of the motor changes, adjusting the target rotating speed of the motor according to the new load of the motor, and determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the new load, and recording the torque as the target torque of the motor.

In some embodiments, two or more different voltage intervals of the one or more voltage intervals comprise: a first voltage interval and a second voltage interval; the voltage amplitude of the first voltage interval is higher than that of the second voltage interval; the control unit adjusts the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, and the control unit comprises the following steps: if the voltage interval of the bus voltage of the motor is the first voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, and the first duty ratio of the PWM signal of the exciting voltage of the motor is obtained and is used as the current duty ratio of the PWM signal of the exciting voltage of the motor; if the voltage interval of the bus voltage of the motor is the second voltage interval, increasing the duty ratio of the PWM signal of the exciting voltage of the motor to obtain the second duty ratio of the PWM signal of the exciting voltage of the motor, and taking the second duty ratio as the current duty ratio of the PWM signal of the exciting voltage of the motor; wherein the second duty cycle of the PWM signal of the excitation voltage of the motor is greater than the first duty cycle of the PWM signal of the excitation voltage of the motor.

In some embodiments, further comprising: the control unit is further configured to determine whether the variation of the bus voltage of the motor exceeds a set voltage variation range in the process of controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor; the control unit is further configured to re-determine, based on the range of the preset voltage range, a range in which the bus voltage of the motor is located in the range of the preset voltage range, as a new voltage range of the bus voltage of the motor, if it is determined that the variation of the bus voltage of the motor has exceeded the set voltage variation range; the control unit is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the new bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the new motor; the control unit is further configured to control output of the PWM signal of the exciting voltage of the motor according to a current duty ratio of the PWM signal of the exciting voltage of the new motor, so that torque actually output by the motor when the motor reaches a target rotational speed of the motor is a target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

In accordance with another aspect of the present invention, there is provided an electric motor comprising: the start control device of the motor is described above.

In accordance with the above method, a further aspect of the present invention provides a storage medium, where the storage medium includes a stored program, and when the program runs, the device where the storage medium is controlled to execute the above method for controlling the start of the motor.

Therefore, under the condition of voltage starting, the scheme of the invention obtains the bus voltage of the motor, determines the voltage interval corresponding to the bus voltage of the motor, and marks the voltage interval as the bus voltage of the motor; acquiring a target rotating speed (such as a preset rotating speed) of the motor when the motor is started, and determining a torque of the motor at a target rotating speed point (such as a torque T of the motor at the preset rotating speed point); if the voltage interval of the bus voltage of the motor is in a low voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is increased, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the first starting time; if the voltage interval of the bus voltage of the motor is in a high voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the second starting time; the difference between the first starting time and the second starting time is the starting time difference and is within a set error range; therefore, the duty ratio of the PWM signal of the exciting voltage in the starting process of the motor is adjusted according to different starting voltages of the motor, the difference of starting time of the motor under different starting voltages is reduced, and the user experience is improved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical scheme of the invention is further described in detail through the drawings and the embodiments.

Drawings

FIG. 1 is a flow chart of an embodiment of a method for controlling the start of an electric motor according to the present invention;

FIG. 2 is a flow chart of an embodiment of a process for dynamically adjusting the duty cycle of PWM signals of the excitation voltage of a motor according to the variation of the bus voltage of the motor in the method of the present invention;

FIG. 3 is a schematic diagram illustrating an embodiment of a motor start control device according to the present invention;

FIG. 4 is a schematic diagram of a constant torque start logic of an embodiment of a method for controlling constant torque start of a high speed motor;

FIG. 5 is a schematic diagram of PWM signal output state of the high-speed motor at high voltage start;

fig. 6 is a schematic diagram of PWM signal output state of the high-speed motor at low voltage start.

In the embodiment of the present invention, reference numerals are as follows, in combination with the accompanying drawings:

102-an acquisition unit; 104-a control unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In view of this, the adjustment of the excitation voltage of the motor can be achieved by an adjustment of the duty cycle of the PWM signal. The PWM is essentially pulse width modulation (i.e., pulse width modulation) in which the excitation voltage of the motor can be converted from a dc voltage to an analog signal of different voltage values by outputting different duty cycles. Therefore, the pulse width of the output PWM signal of the exciting voltage of the motor can be adjusted to realize the adjustment of the rotating speed of the motor, so that the motor can obtain the same torque under different starting voltages no matter in the process of low-voltage or high-voltage starting when reaching the same preset rotating speed; wherein the torque is the torque when the same preset rotating speed is reached, and the corresponding starting voltage corresponds to the corresponding starting torque.

Under the condition that the same gear signal is electrified, the initial starting torque of the motor is smaller during low-voltage starting, and if the starting voltage is increased at the moment by the fixed duty ratio change rate, the starting time of the motor reaching the preset gear rotating speed is longer than the starting time of the motor reaching the preset gear rotating speed during higher-voltage starting. Particularly in the field of high-speed motors, because the high-gear rotating speed is very high, for example, the rotating speed can reach 100krpm (i.e. kilo-revolutions per minute), the starting time for reaching the preset high-gear rotating speed when different high and low voltages are started is greatly different, and the use experience of users is greatly affected. The initial starting torque of the motor refers to starting torque B1 corresponding to each starting voltage A1 when the motor is started; assuming that the target torque of the motor is B2, it is intended to change the torque of the motor from B1 to B2, typically A1 is changed to the start voltage A2 corresponding to the target torque B2 at a fixed rate of change, and when the start voltage is low, i.e., the value of A1 is low, the more time it takes to change to A2. Two factors for determining the motor torque are provided, firstly, when a speed regulation signal (such as a VSP signal of the motor) of the motor is fixed, the lower the exciting voltage of the motor is, the lower the starting torque of the motor is; when the exciting voltage of the motor is fixed, the lower the speed regulating signal of the motor is, the lower the starting torque of the motor is.

The starting of the low-speed motor is usually carried out by adopting a mode of firstly opening a loop to strongly drag to increase current, then cutting the rotating speed or power and adopting a mode of closing the loop to start. The motor of the high-speed motor such as a dust collector has larger required starting torque, and the motor power of the dust collector is in a real-time fluctuation state due to the real-time change of the size of the air inlet of the dust collector, namely the motor rotation speed shaking phenomenon caused by unstable motor power of the dust collector is caused. For example: because the speed of the high-speed motor varies greatly, it is often expressed as a speed varying from 0 rpm to 10 rpm; the low-speed motor often shows a change from 0 rotation speed to 2000 rotation speed per minute, when the low-speed motor climbs to 2000 rotation speed per minute according to a fixed change rate, the low-speed motor takes a long time (usually more than 5 s), and when the low-speed motor climbs to a preset rotation speed of 10 ten thousand rotation speed per minute according to the fixed change rate climbing mode, the low-speed motor needs to take a long time, so that the production efficiency of a production line is reduced, and the user experience is poor. The starting scheme in the related scheme adopts a mode of firstly opening a loop to strongly drag to increase current, then cutting rotating speed or power and adopting a mode of closing a loop to start, when preset torque is not reached, the starting scheme can only increase with fixed change rate, can not solve the problem of excessively long consumed time, can also lead to a high-speed motor such as motor rotating speed shaking phenomenon caused by unstable motor power of a dust collector, and can not realize better starting effect, so that a starting control method of the motor is needed to be designed, and particularly, the constant torque starting control method suitable for the high-speed motor is needed to be designed. Therefore, the scheme of the invention provides a starting control method of a motor, in particular to a constant torque starting control method suitable for a high-speed motor.

The scheme of the invention mainly relates to the field of high-speed motors, and aims to solve the problem that abnormal vibration of the motor is caused by overlarge change of the rotating speed and torque of the motor so as to influence the performance of the motor when the rotating speed of the motor reaches a preset rotating speed point in the process that the rotating speed of the motor reaches a preset rotating speed point when the motor is started at a lower voltage (such as a bus voltage Vdc of 18V) or a higher voltage (such as a bus voltage Vdc of 30V). The motor is started at lower voltage or higher voltage, in the process of reaching a preset rotating speed point, abnormal shaking of the motor is caused by overlarge rotating speed change, for example, the torque is lower during low-voltage starting, the torque is increased during high-voltage starting, and finally the problems that the performance of the motor is affected due to overlarge rotating speed change are solved. For example: abnormal vibration of the motor can cause the power module of the motor to generate heat, and the power module is extremely easy to damage or directly damage. When the motor is started at low voltage, the motor rotating speed is relatively low; if the PWM signals with the same duty ratio are output to start the motor at the moment, the torque of the motor reaching the preset rotating speed point is lower, and similarly, when the starting voltage is increased, the torque of the motor reaching the preset rotating speed point is increased. According to the constant torque starting control method suitable for the high-speed motor, the same torque can be obtained when the motor reaches the same preset rotating speed point under the condition of starting at different voltages, the problem that the starting time difference of the high-speed motor is large under different starting voltages is solved, and therefore the use experience of a user is improved. Meanwhile, the phenomenon that the power is unstable after the rotating speed of the motor reaches a preset gear is avoided when the motor is started at a lower voltage or a higher voltage, so that the running performance of the motor is improved.

Considering that the initial starting torque of the motor at low voltage starting is smaller given the same gear signal power-up, if the starting voltage is increased at the fixed duty ratio change rate at this time, the starting time for the motor to reach the predetermined gear rotational speed is longer than that at higher voltage starting. Particularly in the field of high-speed motors, since the high-gear rotating speed is very high (for example, the rotating speed can reach 100 krpm), the starting time for reaching the preset high-gear rotating speed when different high-low voltages are started is greatly different, so that different duty ratio change rates are very necessary for different starting voltage ranges. According to an embodiment of the present invention, there is provided a method for controlling the start-up of an electric motor, as shown in fig. 1, which is a schematic flow chart of an embodiment of the method of the present invention. The motor start control method may include: step S110 to step S150.

At step S110, in the case where the motor needs to be started, a target rotational speed of the motor is obtained, and a bus voltage of the motor is obtained. The target rotational speed (e.g., a predetermined rotational speed) of the motor is the rotational speed at which the motor completes the start-up, that is, the rotational speed at which the motor can be normally started. The bus voltage of the motor is the voltage of direct current after alternating current is rectified by a rectifier bridge on the power supply side of the motor.

At step S120, a torque required to be output by the motor in the case of reaching the target rotational speed of the motor is determined according to the target rotational speed of the motor, and is noted as a target torque of the motor (e.g., a torque T of the motor at a predetermined rotational speed point).

In some embodiments, determining the torque that the motor needs to output when the target rotational speed of the motor is reached according to the target rotational speed of the motor in step S120, denoted as the target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point), includes any one of the following determination cases:

first determination case: when the load of the motor is fixed, determining the torque required to be output by the motor when the motor reaches the target rotation speed according to the corresponding relation between the set rotation speed and the set torque of the motor under the load, and recording the torque as the target torque (such as the torque T of the motor at a preset rotation speed point) of the motor. The phenomenon of torque change of the motor is that the rotating speed of the motor changes, and when the load is fixed, the change conditions of the motor and the rotating speed are the same, namely the rotating speed changes along with the change of the torque.

Second determination case: and when the load of the motor changes, adjusting the target rotating speed of the motor according to the new load of the motor, and determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the new load, wherein the torque is recorded as the target torque (such as the torque T of the motor at a preset rotating speed point) of the motor.

Fig. 4 is a schematic diagram of a constant torque start logic of an embodiment of a control method for constant torque start of a high speed motor. As shown in fig. 4, the method for controlling the constant torque start of the high-speed motor provided by the scheme of the invention comprises the following steps: and step 1, detecting the torque T of the motor at a preset rotating speed point. When the motor is started, the main control chip of the motor can detect a preset rotating speed point input by the motor through the rotating speed feedback circuit, and the corresponding torque is judged, namely the torque corresponding to the preset rotating speed point input by the motor is determined and used as the torque T of the motor at the preset rotating speed point.

Specifically, under the condition of fixed motor load, the torque of the motor is in direct proportion to the rotating speed, so the torque T required when the rotating speed of the motor reaches a preset rotating speed point can be determined as the torque T of the motor at the preset rotating speed point through a theoretical and experimental evaluation mode. Wherein, when the load of the motor is fixed, the torque of the motor is proportional to the rotation speed of the motor.

At step S130, a section in which the bus voltage of the motor is located in the range of the preset voltage section is determined based on the range of the preset voltage section, and is denoted as a voltage section of the bus voltage of the motor. The range of the preset voltage interval includes: more than one voltage interval.

Specifically, as shown in fig. 4, the method for controlling the constant torque start of the high-speed motor according to the scheme of the invention further comprises the following steps: and 2, detecting a voltage interval where the bus voltage Vdc of the motor is located. When the motor is started, the bus voltage Vdc of the motor is detected through the voltage sampling circuit, and the bus voltage Vdc of the motor detected in real time is fed back to the main control chip. At this time, the main control chip determines a voltage interval (such as a low voltage interval or a high voltage interval) where the bus voltage Vdc of the motor is located at this time through software according to the bus voltage Vdc of the motor fed back by the voltage sampling circuit in real time. The voltage interval is defined by the user according to the actual situation, and is similar to the definition modes of speed regulating signals and gears.

At step S140, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted according to the voltage interval of the bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor. Wherein the excitation voltage of the motor is a supply voltage when the motor operates based on a voltage supplied to a winding of the motor. The current duty ratio of the PWM signal of the exciting voltage of the motor is a duty ratio which can enable the motor to start with constant torque and the starting time is within a set starting time range. Specifically, the torque output by the motor when the target rotational speed of the motor is reached can be a target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage range of the bus voltage of the motor is two or more different voltage ranges among the one or more voltage ranges, the start time difference, which is the difference between the times at which the bus voltage of the motor reaches the target rotational speed of the motor in the two or more different voltage ranges, may be set within a set error range. Specifically, as shown in fig. 4, the method for controlling the constant torque start of the high-speed motor according to the scheme of the invention further comprises the following steps: and 3, outputting PWM signals with corresponding amplitude and pulse width by the main control chip according to a voltage interval where the bus voltage Vdc of the motor is located, so that the torque output by the motor is equal to the torque T of the motor at a preset rotating speed point.

In some embodiments, two or more different voltage intervals of the one or more voltage intervals comprise: a first voltage interval and a second voltage interval. The voltage amplitude of the first voltage interval is higher than that of the second voltage interval. The first voltage interval is a high voltage interval, and the second voltage interval is a low voltage interval.

In step S140, according to the voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, which includes any one of the following adjustment situations:

first adjustment scenario: and if the voltage interval of the bus voltage of the motor is the first voltage interval, reducing the duty ratio of the PWM signal of the exciting voltage of the motor to obtain the first duty ratio of the PWM signal of the exciting voltage of the motor, and taking the first duty ratio as the current duty ratio of the PWM signal of the exciting voltage of the motor.

Second adjustment scenario: and if the voltage interval of the bus voltage of the motor is the second voltage interval, increasing the duty ratio of the PWM signal of the exciting voltage of the motor to obtain the second duty ratio of the PWM signal of the exciting voltage of the motor, and taking the second duty ratio as the current duty ratio of the PWM signal of the exciting voltage of the motor. Wherein the second duty cycle of the PWM signal of the excitation voltage of the motor is greater than the first duty cycle of the PWM signal of the excitation voltage of the motor.

As shown in fig. 4, the method for controlling the constant torque start of the high-speed motor according to the scheme of the invention further comprises the following steps: in step 3, specifically, when the bus voltage Vdc is in the low voltage region, the duty ratio is increased so that the areas of the PWM signals outputted are the same, that is, the torque T is the same when the motor reaches the same predetermined rotation speed point. On the contrary, when the bus voltage Vdc is in the high voltage region, the duty ratio is reduced, and when the motor reaches the same preset rotation speed point, the output PWM signals have the same area, namely the torque T is the same. The amplitude or proportion of the increased duty ratio and the decreased duty ratio can be obtained by looking up a table through a preset corresponding relation table.

According to the scheme, by detecting different voltage starting values of the motor, starting control under different starting voltage conditions is optimized, for example, when the starting voltage of the motor is low, the duty ratio of an output PWM signal of the starting voltage of the motor is increased. However, when the starting voltage of the motor is higher, the duty ratio of the output PWM signal of the starting voltage of the motor is reduced, so that the motor can obtain the same torque when reaching the same preset rotating speed point under the condition of starting at different voltages, the problem that the starting time difference of the high-speed motor is larger under different starting voltages is solved, and the use experience of a user is improved. Meanwhile, the phenomenon that the power is unstable after the rotating speed of the motor reaches a preset gear is avoided when the motor is started at a lower voltage or a higher voltage, so that the running performance of the motor is improved.

In some embodiments, in a case where a voltage section of a bus voltage of the motor is the first voltage section, an excitation voltage of the motor is noted as a first excitation voltage of the motor. And when the voltage interval of the bus voltage of the motor is the second voltage interval, the exciting voltage of the motor is recorded as the second exciting voltage of the motor.

Wherein the product of the amplitude of the first exciting voltage of the motor and the first duty ratio of the PWM signal of the exciting voltage of the motor is equal to the product of the amplitude of the second exciting voltage of the motor and the second duty ratio of the PWM signal of the exciting voltage of the motor.

Fig. 5 is a schematic diagram of a PWM signal output state of the high-speed motor at the time of high-voltage start, and fig. 6 is a schematic diagram of a PWM signal output state of the high-speed motor at the time of low-voltage start. Through step 1 to step 3 in the example shown in fig. 4, the main control chip determines the corresponding torque required, i.e. the torque T of the motor at the predetermined rotational speed point, by detecting the predetermined rotational speed point of the motor. Meanwhile, the real-time bus voltage Vdc of the input side of the motor is detected, so that the main control chip outputs pulse signals with the same area (as in the shaded parts of fig. 5 and 6) under different bus voltages Vdc, namely, the motor outputs the same torque T and outputs an excitation voltage PWM signal corresponding to the duty ratio D.

In fig. 5, the effective exciting voltage value s1=u1×d1, d1=t1/t. The excitation voltage effective value s2=u2×d2 in fig. 6, d2=t2/t. S1 and S2 are effective values of exciting voltage, U1 and U2 are amplitude values of the exciting voltage, and D1 and D2 are duty ratios of the exciting voltage. t is a period, t1 is a time of the excitation voltage PWM signal output at the time of starting the high voltage U1 in the period t, and t2 is a time of the excitation voltage PWM signal output at the time of starting the low voltage U2 in the period t.

In the example shown in fig. 6, the waveform of the exciting voltage PWM signal in the example shown in fig. 5 is lower than the PWM signal amplitude of the exciting voltage output at the time of starting the low voltage U2, and the PWM signal amplitude of the exciting voltage output at the time of starting the higher voltage U1, compared with the example shown in fig. 5. However, the duty ratio D2 of the PWM signal of the exciting voltage outputted at the time of starting the low voltage U2 is higher than the duty ratio D1 of the PWM signal of the exciting voltage outputted at the time of starting the higher voltage U1. However, the area S2 of the PWM signal of the exciting voltage output at the time of starting the low voltage U2 is the same as the area S1 of the PWM signal of the exciting voltage output at the time of starting the high voltage U1, even if s1=s2, so that the same torque can be obtained when the same predetermined rotational speed point is reached in the case of keeping the motor started at different voltages, the time to reach the predetermined rotational speed point in the case of starting the low voltage is reduced, and the difference in the starting time to reach the predetermined rotational speed in the case of starting the motor at different voltages of the high voltage U1 and the low voltage U2 is shortened.

According to the scheme, different voltage starting values of the motor and the torque of the preset rotating speed point of the motor are detected, and when the starting voltage of the motor is low, the duty ratio of a PWM signal for outputting the exciting voltage of the motor is increased. When the starting voltage of the motor is higher, the duty ratio of the PWM signal of the exciting voltage of the output motor is reduced, so that the motor can obtain the same torque when reaching the same preset rotating speed point under the condition of starting at different voltages, the situation that the different starting voltages can reach the target torque in close time can be ensured, the problem that the starting time difference of the high-speed motor is larger under different starting voltages is solved, and the use experience of a user is improved.

At step S150, the output of the PWM signal of the exciting voltage of the motor is controlled according to the current duty ratio of the PWM signal of the exciting voltage of the motor, so that the torque actually output by the motor when the target rotational speed of the motor is reached is the target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

According to the scheme, different duty ratio change rates are set according to different starting voltages, and the provided constant torque starting control method for the high-speed motor is used for adjusting the duty ratio change rate of an output PWM signal of the starting voltage value of the motor by detecting the starting voltage value of the motor, so that when the motor starts at different high and low voltages, the motor can output the same torque at the starting time close to the starting time, and the rotating speed (such as the target rotating speed) of a preset gear is reached. Thus, the motor outputs corresponding duty ratio increasing rate under different starting voltages to replace the full starting voltage range (such as 50V-500V of the direct current voltage DC) to output fixed duty ratio changing rate, the problem of larger starting time difference of the high-speed motor under different starting voltages is solved, and the use experience of a user is improved.

In some embodiments, the method for controlling start-up of a motor according to the present invention further includes, after controlling output of the PWM signal of the exciting voltage of the motor according to a current duty ratio of the PWM signal of the exciting voltage of the motor: and dynamically adjusting the duty ratio of the PWM signal of the exciting voltage of the motor according to the change condition of the bus voltage of the motor.

The following is a flowchart of an embodiment of a process for dynamically adjusting the duty ratio of the PWM signal of the exciting voltage of the motor according to the change condition of the bus voltage of the motor in the method of the present invention shown in fig. 2, further describing a specific process of the process for dynamically adjusting the duty ratio of the PWM signal of the exciting voltage of the motor according to the change condition of the bus voltage of the motor, which includes: step S210 to step S240.

Step S210, determining whether the variation of the bus voltage of the motor exceeds the set voltage variation range in the process of controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor.

Step S220, if it is determined that the variation of the bus voltage of the motor has exceeded the set voltage variation range, determining, again, based on the range of the preset voltage ranges, the range in which the bus voltage of the motor is located in the range of the preset voltage ranges, and recording the range as the new voltage range of the bus voltage of the motor.

Further, in step S230, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted according to the new voltage section of the bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor.

Further, in step S240, the output of the PWM signal of the exciting voltage of the motor is controlled according to the current duty ratio of the PWM signal of the exciting voltage of the new motor, so that the torque actually output by the motor when the target rotational speed of the motor is reached is the target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

As shown in fig. 5, when the motor is started at the high voltage U1, the output of the PWM signal amplitude of the exciting voltage is higher, and the motor can reach the predetermined rotation speed point in a shorter time. However, in order to avoid the phenomenon that the motor rotates at a speed due to power fluctuation caused by load variation, a pulse width of a PWM signal with a shorter exciting voltage needs to be output at this time, that is, a duty ratio of the PWM signal with a smaller exciting voltage needs to be reduced, and a PWM signal with a smaller duty ratio needs to be output, for example, a PWM signal with a duty ratio of D1 is output, so that not only is the motor ensured to reach a predetermined rotation speed point in a properly short time, but also the phenomenon that the motor rotates at a speed due to power fluctuation caused by load variation is avoided, and stable operation of the motor is ensured. When the bus voltage Vdc is gradually reduced, the amplitude of the PWM signal of the exciting voltage is also reduced, so that the same torque can be obtained when the motor reaches the same preset rotating speed point under the condition of starting the lower bus voltage, and the same torque, namely the same pulse area of the PWM signal amplitude of the exciting voltage, needs to be output at the moment when the motor is started with the high voltage U1, so that the duty ratio of the PWM signal is also increased.

As shown in fig. 6, the PWM signal amplitude of the exciting voltage output at the time of starting the low voltage U2 is low, and the PWM signal amplitude of the exciting voltage output at the time of starting the higher voltage U1 is low, so that the motor can reach the predetermined rotation speed point in a shorter time when the low voltage U2 is started and can obtain the same torque T as the high voltage U1, the duty ratio of the PWM signal of the exciting voltage is increased at this time, that is, the duty ratio D2 of the PWM signal of the exciting voltage is obtained, the area S2 of the PWM signal of the exciting voltage output at the time of starting the low voltage U2 is made the same as the area S1 of the PWM signal of the exciting voltage output at the time of starting the high voltage U1, so that the motor can obtain the same rotation speed as the high voltage U1 is started when the low voltage U2 is started, and the time when the motor reaches the predetermined rotation speed point is reduced when the low voltage U2 is started.

According to the scheme, aiming at the power change condition caused by frequent load change after the rotating speed of the motor reaches the preset gear, when the rotating speed of the motor reaches the preset gear, the duty ratio of the output PWM signal of the exciting voltage of the motor is adjusted in real time, so that the phenomenon of motor rotating speed shaking caused by power fluctuation caused by load change of the motor is solved, and the running stability of the motor is improved. Therefore, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to ensure that the power of the motor reaches the power of the preset gear, so that the phenomenon that the power is unstable after the rotating speed of the motor reaches the preset gear when the motor is started at a lower voltage or a higher voltage is avoided, and the running performance of the motor is improved.

The gear of the motor can be divided according to the real-time rotating speed of the motor, for example, 0rpm corresponds to M1 gear, 1000rpm corresponds to MH gear, and the like. The power influence of the motor is determined by voltage and current, the voltage is the external input voltage (namely the exciting voltage of the motor), the main motor speed regulating signal for controlling the current is the voltage, when the speed regulating signal VSP of the motor is increased, the controller of the motor can control the input current of the motor to be increased, and the power of the motor is increased. That is, when the exciting voltage of the motor is fixed, the speed regulating signal VSP of the motor is excessively changed, and the real-time current can be obtained through the sampling circuit, that is, the real-time change condition of the load power can be detected. Wherein power of the motor = product of control current of the motor and external input voltage.

In some alternative embodiments, in non-high speed motor applications, if a phenomenon occurs in which the difference between the high and low voltage start times is large, the phenomenon can be avoided by changing the output duty cycle change rate at different start voltages. The motor rotating speed is greater than 1 ten thousand revolutions per minute, namely the high-speed motor field.

By adopting the technical scheme of the embodiment, under the condition of voltage starting, the bus voltage of the motor is obtained, the voltage interval corresponding to the bus voltage of the motor is determined, and the voltage interval is recorded as the voltage interval where the bus voltage of the motor is located. The target rotating speed (such as a preset rotating speed) of the motor when the motor is started is obtained, and the torque of the motor at the target rotating speed point (such as the torque T of the motor at the preset rotating speed point) is determined. And if the voltage interval of the bus voltage of the motor is in a low voltage interval in the range of the preset voltage interval, increasing the duty ratio of the PWM signal of the exciting voltage of the motor so that the torque output by the motor when the motor reaches the target rotating speed in the first starting time is the torque T. And if the voltage interval of the bus voltage of the motor is in a high voltage interval in the range of the preset voltage interval, reducing the duty ratio of the PWM signal of the exciting voltage of the motor so that the torque output by the motor when the motor reaches the target rotating speed in the second starting time is the torque T. The difference between the first starting time and the second starting time is the starting time difference and is within a set error range. Therefore, the duty ratio of the PWM signal of the exciting voltage in the starting process of the motor is adjusted according to different starting voltages of the motor, the difference of starting time of the motor under different starting voltages is reduced, and the user experience is improved.

Considering that the initial starting torque of the motor at low voltage starting is smaller given the same gear signal power-up, if the starting voltage is increased at the fixed duty ratio change rate at this time, the starting time for the motor to reach the predetermined gear rotational speed is longer than that at higher voltage starting. Particularly in the field of high-speed motors, since the high-gear rotating speed is very high (for example, the rotating speed can reach 100 krpm), the starting time for reaching the preset high-gear rotating speed when different high-low voltages are started is greatly different, so that different duty ratio change rates are very necessary for different starting voltage ranges. According to an embodiment of the present invention, there is also provided a start control apparatus of an electric motor corresponding to a start control method of the electric motor. Referring to fig. 3, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The start control device of the motor may include: an acquisition unit 102 and a control unit 104.

Wherein, the obtaining unit 102 is configured to obtain a target rotation speed of the motor and obtain a bus voltage of the motor when the motor needs to be started. The target rotational speed (e.g., a predetermined rotational speed) of the motor is the rotational speed at which the motor completes the start-up, that is, the rotational speed at which the motor can be normally started. The bus voltage of the motor is the voltage of direct current after alternating current is rectified by a rectifier bridge on the power supply side of the motor. The specific function and process of the acquisition unit 102 refer to step S110.

A control unit 104 configured to determine, based on the target rotational speed of the motor, a torque that the motor needs to output if the target rotational speed of the motor is reached, denoted as a target torque of the motor (e.g., a torque T of the motor at a predetermined rotational speed point). The specific function and process of the control unit 104 refer to step S120.

In some embodiments, the control unit 104 determines, according to the target rotation speed of the motor, a torque that the motor needs to output when reaching the target rotation speed of the motor, and marks the torque as a target torque of the motor (such as a torque T of the motor at a predetermined rotation speed point), including any one of the following determination cases:

first determination case: the control unit 104 is specifically further configured to determine, when the load of the motor is fixed, a torque that the motor needs to output when the motor reaches the target rotational speed according to a correspondence between the set rotational speed and the set torque of the motor under the load, and record the torque as a target torque of the motor (e.g., a torque T of the motor at a predetermined rotational speed point). The phenomenon of torque change of the motor is that the rotating speed of the motor changes, and when the load is fixed, the change conditions of the motor and the rotating speed are the same, namely the rotating speed changes along with the change of the torque.

Second determination case: the control unit 104 is specifically further configured to adjust, when the load of the motor changes, the target rotation speed of the motor according to the new load of the motor, and determine, according to the correspondence between the set rotation speed and the set torque of the motor under the new load, the torque that the motor needs to output when reaching the target rotation speed, and record the torque as the target torque of the motor (such as the torque T of the motor at the predetermined rotation speed point).

FIG. 4 is a schematic diagram of a constant torque start logic of an embodiment of a high speed motor constant torque start control. As shown in fig. 4, the high-speed motor constant torque starting control device provided by the scheme of the invention comprises: and step 1, detecting the torque T of the motor at a preset rotating speed point. When the motor is started, the main control chip of the motor can detect a preset rotating speed point input by the motor through the rotating speed feedback circuit, and the corresponding torque is judged, namely the torque corresponding to the preset rotating speed point input by the motor is determined and used as the torque T of the motor at the preset rotating speed point.

The control unit 104 is further configured to determine, based on a range of preset voltage intervals, an interval in which the bus voltage of the motor is located in the range of the preset voltage intervals, and record the interval as a voltage interval of the bus voltage of the motor. The range of the preset voltage interval includes: more than one voltage interval. The specific function and processing of the control unit 104 is also referred to in step S130.

Specifically, as shown in fig. 4, the high-speed motor constant torque starting control device provided by the scheme of the invention further comprises: and 2, detecting a voltage interval where the bus voltage Vdc of the motor is located. When the motor is started, the bus voltage Vdc of the motor is detected through the voltage sampling circuit, and the bus voltage Vdc of the motor detected in real time is fed back to the main control chip. At this time, the main control chip determines a voltage interval (such as a low voltage interval or a high voltage interval) where the bus voltage Vdc of the motor is located at this time through software according to the bus voltage Vdc of the motor fed back by the voltage sampling circuit in real time. The voltage interval is defined by the user according to the actual situation, and is similar to the definition modes of speed regulating signals and gears.

The control unit 104 is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor. Wherein the excitation voltage of the motor is a supply voltage when the motor operates based on a voltage supplied to a winding of the motor. The current duty ratio of the PWM signal of the exciting voltage of the motor is a duty ratio which can enable the motor to start with constant torque and the starting time is within a set starting time range. Specifically, the torque output by the motor when the target rotational speed of the motor is reached can be a target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage range of the bus voltage of the motor is two or more different voltage ranges among the one or more voltage ranges, the start time difference, which is the difference between the times at which the bus voltage of the motor reaches the target rotational speed of the motor in the two or more different voltage ranges, may be set within a set error range. The specific function and process of the control unit 104 also refer to step S140.

Specifically, as shown in fig. 4, the high-speed motor constant torque starting control device provided by the scheme of the invention further comprises: and 3, outputting PWM signals with corresponding amplitude and pulse width by the main control chip according to a voltage interval where the bus voltage Vdc of the motor is located, so that the torque output by the motor is equal to the torque T of the motor at a preset rotating speed point.

The control unit 104 adjusts the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor, to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, which includes any one of the following adjustment situations:

first adjustment scenario: the control unit 104 is specifically further configured to reduce the duty ratio of the PWM signal of the excitation voltage of the motor if the voltage interval of the bus voltage of the motor is the first voltage interval, and obtain the first duty ratio of the PWM signal of the excitation voltage of the motor as the current duty ratio of the PWM signal of the excitation voltage of the motor.

Second adjustment scenario: the control unit 104 is specifically further configured to increase the duty ratio of the PWM signal of the excitation voltage of the motor if the voltage interval of the bus voltage of the motor is the second voltage interval, and obtain the second duty ratio of the PWM signal of the excitation voltage of the motor as the current duty ratio of the PWM signal of the excitation voltage of the motor. Wherein the second duty cycle of the PWM signal of the excitation voltage of the motor is greater than the first duty cycle of the PWM signal of the excitation voltage of the motor.

As shown in fig. 4, the high-speed motor constant torque starting control device provided by the scheme of the invention further comprises: in step 3, specifically, when the bus voltage Vdc is in the low voltage region, the duty ratio is increased so that the areas of the PWM signals outputted are the same, that is, the torque T is the same when the motor reaches the same predetermined rotation speed point. On the contrary, when the bus voltage Vdc is in the high voltage region, the duty ratio is reduced, and when the motor reaches the same preset rotation speed point, the output PWM signals have the same area, namely the torque T is the same.

In some embodiments, in a case where a voltage section of a bus voltage of the motor is the first voltage section, an excitation voltage of the motor is noted as a first excitation voltage of the motor. And when the voltage interval of the bus voltage of the motor is the second voltage interval, the exciting voltage of the motor is recorded as the second exciting voltage of the motor. Wherein the product of the amplitude of the first exciting voltage of the motor and the first duty ratio of the PWM signal of the exciting voltage of the motor is equal to the product of the amplitude of the second exciting voltage of the motor and the second duty ratio of the PWM signal of the exciting voltage of the motor.

The control unit 104 is further configured to control the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor, so that the torque actually output by the motor when the target rotational speed of the motor is reached is the target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range. The specific function and process of the control unit 104 also refer to step S150.

According to the scheme, different duty ratio change rates are set for different starting voltages, and the provided constant torque starting control device for the high-speed motor is used for adjusting the duty ratio change rate of an output PWM signal of the starting voltage value of the motor by detecting the starting voltage value of the motor, so that when the motor starts at different high and low voltages, the motor can output the same torque at the starting time close to the starting time, and the rotating speed (such as the target rotating speed) of a preset gear is reached. Thus, the motor outputs corresponding duty ratio increasing rate under different starting voltages to replace the full starting voltage range (such as 50V-500V of the direct current voltage DC) to output fixed duty ratio changing rate, the problem of larger starting time difference of the high-speed motor under different starting voltages is solved, and the use experience of a user is improved.

In some embodiments, the start control device for a motor according to the aspect of the present invention, the control unit 104, after controlling the output of the PWM signal of the excitation voltage of the motor according to the current duty ratio of the PWM signal of the excitation voltage of the motor, further includes: the control unit 104 dynamically adjusts the duty ratio of the PWM signal of the exciting voltage of the motor according to the change condition of the bus voltage of the motor.

The control unit 104 is further configured to determine whether the amount of change in the bus voltage of the motor has exceeded a set voltage change range during the control of the output of the PWM signal of the exciting voltage of the motor at the current duty ratio of the PWM signal of the exciting voltage of the motor. The specific function and process of the control unit 104 also refer to step S210.

The control unit 104 is further configured to, if it is determined that the amount of change in the bus voltage of the motor has exceeded the set voltage change range, redetermine, based on the range of the preset voltage ranges, a range in which the bus voltage of the motor is located in the range of the preset voltage ranges, as a new voltage range of the bus voltage of the motor. The specific function and process of the control unit 104 is also referred to as step S220.

Furthermore, the control unit 104 is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the new bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the new motor. The specific function and process of the control unit 104 is also referred to as step S230.

Further, the control unit 104 is further configured to control the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the new motor, so that the torque actually output by the motor when the target rotational speed of the motor is reached is the target torque of the motor (e.g., the torque T of the motor at a predetermined rotational speed point). When the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range. The specific function and process of the control unit 104 also refer to step S240.

Since the processes and functions implemented by the apparatus of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing methods, the descriptions of the embodiments are not exhaustive, and reference may be made to the descriptions of the foregoing embodiments and their descriptions are omitted herein.

By adopting the technical scheme, under the condition of voltage starting, the bus voltage of the motor is obtained, the voltage interval corresponding to the bus voltage of the motor is determined, and the voltage interval is recorded as the voltage interval where the bus voltage of the motor is positioned; acquiring a target rotating speed (such as a preset rotating speed) of the motor when the motor is started, and determining a torque of the motor at a target rotating speed point (such as a torque T of the motor at the preset rotating speed point); if the voltage interval of the bus voltage of the motor is in a low voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is increased, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the first starting time; if the voltage interval of the bus voltage of the motor is in a high voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the second starting time; the difference between the first starting time and the second starting time is the starting time difference and is within a set error range; by obtaining the same torque, the situation that different starting voltages can reach the target torque in close time can be guaranteed, the problem that the starting time difference of the high-speed motor is large under different starting voltages is solved, and therefore the use experience of a user is improved.

According to an embodiment of the present invention, there is also provided a motor corresponding to a start control device of the motor. The motor may include: the start control device of the motor is described above.

Since the processes and functions implemented by the motor of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing apparatus, the description of the present embodiment is not exhaustive, and reference may be made to the related descriptions of the foregoing embodiments, which are not repeated herein.

By adopting the technical scheme, under the condition of voltage starting, the bus voltage of the motor is obtained, the voltage interval corresponding to the bus voltage of the motor is determined, and the voltage interval is recorded as the voltage interval where the bus voltage of the motor is positioned; acquiring a target rotating speed (such as a preset rotating speed) of the motor when the motor is started, and determining a torque of the motor at a target rotating speed point (such as a torque T of the motor at the preset rotating speed point); if the voltage interval of the bus voltage of the motor is in a low voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is increased, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the first starting time; if the voltage interval of the bus voltage of the motor is in a high voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the second starting time; the difference between the first starting time and the second starting time is the starting time difference, and in the set error range, the phenomenon that the power is unstable after the rotating speed of the motor reaches a preset gear when the motor is started at a lower voltage or a higher voltage is avoided, so that the running performance of the motor is improved.

According to an embodiment of the present invention, there is also provided a storage medium corresponding to a start-up control method of an electric motor, the storage medium including a stored program, wherein the apparatus in which the storage medium is controlled to execute the start-up control method of an electric motor described above when the program runs.

Since the processes and functions implemented by the storage medium of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing methods, the descriptions of the present embodiment are not exhaustive, and reference may be made to the related descriptions of the foregoing embodiments, which are not repeated herein.

By adopting the technical scheme, under the condition of voltage starting, the bus voltage of the motor is obtained, the voltage interval corresponding to the bus voltage of the motor is determined, and the voltage interval is recorded as the voltage interval where the bus voltage of the motor is positioned; acquiring a target rotating speed (such as a preset rotating speed) of the motor when the motor is started, and determining a torque of the motor at a target rotating speed point (such as a torque T of the motor at the preset rotating speed point); if the voltage interval of the bus voltage of the motor is in a low voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is increased, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the first starting time; if the voltage interval of the bus voltage of the motor is in a high voltage interval in the range of the preset voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, so that the torque output by the motor is the torque T when the motor reaches the target rotating speed in the second starting time; the difference between the first starting time and the second starting time is the starting time difference, and in a set error range, the problem that the starting time difference of the high-speed motor is large under different starting voltages is solved, so that the use experience of a user is improved.

In summary, it is readily understood by those skilled in the art that the above-described advantageous ways can be freely combined and superimposed without conflict.

The above description is only an example of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A startup control method of an electric motor, characterized by comprising:

under the condition that the motor needs to be started, acquiring a target rotating speed of the motor and acquiring a bus voltage of the motor; the target rotating speed of the motor is the rotating speed when the motor is started;

determining the torque required to be output by the motor when the target rotating speed of the motor is reached according to the target rotating speed of the motor, and recording the torque as the target torque of the motor;

determining a section where the bus voltage of the motor is located in the range of the preset voltage section based on the range of the preset voltage section, and recording the section as a voltage section of the bus voltage of the motor; the range of the preset voltage interval includes: more than one voltage interval;

According to the voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor;

controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor so that the torque actually output by the motor when the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

2. The startup control method of an electric motor according to claim 1, characterized in that determining, based on a target rotation speed of the electric motor, a torque that the electric motor needs to output in the case where the target rotation speed of the electric motor is reached, noted as a target torque of the electric motor, includes:

when the load of the motor is fixed, determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the load, and recording the torque as the target torque of the motor;

And when the load of the motor changes, adjusting the target rotating speed of the motor according to the new load of the motor, and determining the torque required to be output by the motor when the motor reaches the target rotating speed according to the corresponding relation between the set rotating speed and the set torque of the motor under the new load, and recording the torque as the target torque of the motor.

3. The method of controlling start-up of an electric motor according to claim 1, wherein two or more different voltage intervals among the one or more voltage intervals include: a first voltage interval and a second voltage interval; the voltage amplitude of the first voltage interval is higher than that of the second voltage interval;

according to the voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, and the method comprises the following steps:

if the voltage interval of the bus voltage of the motor is the first voltage interval, the duty ratio of the PWM signal of the exciting voltage of the motor is reduced, and the first duty ratio of the PWM signal of the exciting voltage of the motor is obtained and is used as the current duty ratio of the PWM signal of the exciting voltage of the motor;

If the voltage interval of the bus voltage of the motor is the second voltage interval, increasing the duty ratio of the PWM signal of the exciting voltage of the motor to obtain the second duty ratio of the PWM signal of the exciting voltage of the motor, and taking the second duty ratio as the current duty ratio of the PWM signal of the exciting voltage of the motor; wherein the second duty cycle of the PWM signal of the excitation voltage of the motor is greater than the first duty cycle of the PWM signal of the excitation voltage of the motor.

4. A start-up control method of an electric motor according to claim 3, wherein in the case where a voltage section of a bus voltage of the electric motor is the first voltage section, an excitation voltage of the electric motor is noted as a first excitation voltage of the electric motor; when the voltage interval of the bus voltage of the motor is the second voltage interval, the exciting voltage of the motor is recorded as the second exciting voltage of the motor;

5. The startup control method of an electric motor according to any one of claims 1 to 4, characterized by further comprising:

determining whether the variation of the bus voltage of the motor exceeds a set voltage variation range or not in the process of controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor;

if the change amount of the bus voltage of the motor is determined to be beyond the set voltage change range, re-determining the range of the bus voltage of the motor in the range of the preset voltage range based on the range of the preset voltage range, and recording the range as a new voltage range of the bus voltage of the motor;

according to the new voltage interval of the bus voltage of the motor, the duty ratio of the PWM signal of the exciting voltage of the motor is adjusted to obtain the current duty ratio of the PWM signal of the exciting voltage of the new motor;

controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the new motor so that the torque actually output by the motor under the condition that the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

6. A start control device for an electric motor, comprising:

an acquisition unit configured to acquire a target rotation speed of the motor and acquire a bus voltage of the motor in a case where the motor needs to be started; the target rotating speed of the motor is the rotating speed when the motor is started;

a control unit configured to determine, based on a target rotational speed of the motor, a torque that the motor needs to output when reaching the target rotational speed of the motor, and to record as a target torque of the motor;

the control unit is further configured to determine, based on a range of preset voltage ranges, a range in which a bus voltage of the motor is located in the range of the preset voltage ranges, and record the range as a voltage range of the bus voltage of the motor; the range of the preset voltage interval includes: more than one voltage interval;

the control unit is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor;

the control unit is further configured to control output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor, so that torque actually output by the motor when the motor reaches the target rotating speed of the motor is the target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

7. The apparatus according to claim 6, wherein the control unit determines, based on a target rotational speed of the motor, a torque that the motor needs to output in a case where the target rotational speed of the motor is reached, as a target torque of the motor, comprising:

8. The start-up control device of the motor according to claim 6, wherein two or more different voltage intervals among the one or more voltage intervals include: a first voltage interval and a second voltage interval; the voltage amplitude of the first voltage interval is higher than that of the second voltage interval;

The control unit adjusts the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the bus voltage of the motor to obtain the current duty ratio of the PWM signal of the exciting voltage of the motor, and the control unit comprises the following steps:

9. The start control device of the motor according to claim 8, wherein when a voltage section of a bus voltage of the motor is the first voltage section, an excitation voltage of the motor is noted as a first excitation voltage of the motor; when the voltage interval of the bus voltage of the motor is the second voltage interval, the exciting voltage of the motor is recorded as the second exciting voltage of the motor;

10. The start-up control device of an electric motor according to any one of claims 6 to 9, characterized by further comprising:

the control unit is further configured to determine whether the variation of the bus voltage of the motor exceeds a set voltage variation range in the process of controlling the output of the PWM signal of the exciting voltage of the motor according to the current duty ratio of the PWM signal of the exciting voltage of the motor;

the control unit is further configured to re-determine, based on the range of the preset voltage range, a range in which the bus voltage of the motor is located in the range of the preset voltage range, as a new voltage range of the bus voltage of the motor, if it is determined that the variation of the bus voltage of the motor has exceeded the set voltage variation range;

the control unit is further configured to adjust the duty ratio of the PWM signal of the exciting voltage of the motor according to the voltage interval of the new bus voltage of the motor, so as to obtain the current duty ratio of the PWM signal of the exciting voltage of the new motor;

The control unit is further configured to control output of the PWM signal of the exciting voltage of the motor according to a current duty ratio of the PWM signal of the exciting voltage of the new motor, so that torque actually output by the motor when the motor reaches a target rotational speed of the motor is a target torque of the motor; when the voltage interval of the bus voltage of the motor is two or more different voltage intervals among the one or more voltage intervals, the difference between the times of reaching the target rotating speed of the motor under the bus voltage of the two or more different voltage intervals, namely the starting time difference, is within a set error range.

11. An electric machine, comprising: a start control device for an electric motor according to any one of claims 6 to 10.

12. A storage medium comprising a stored program, wherein the program, when run, controls a device in which the storage medium is located to perform the start-up control method of the motor according to any one of claims 1 to 5.