阅读说明：本技术 自起动同步电机的控制方法及系统、存储介质、处理器 (Control method and system for self-starting synchronous motor, storage medium and processor ) 是由 史进飞 李霞 陈彬 肖勇 张志东 于 2020-12-17 设计创作，主要内容包括：本发明公开了一种自起动同步电机的控制方法及系统、存储介质、处理器。其中,该方法包括：控制自起动同步电机上电并检测自起动同步电机的转速,其中,自起动同步电机的转速逐渐上升；当自起动同步电机的转速达到第一转速时,控制自起动同步电机的输入电压开始上升；并当自起动同步电机转速达到第二转速时,自起动同步电机输入电压上升至预设电压,其中,第一转速小于第二转速,第二转速小于自起动同步电机的额定转速,预设电压大于自起动同步电机的额定电压；控制输入电压保持为预设电压,直至自起动同步电机的转速第一次达到额定转速。本发明解决了自起动同步电机在起动过程中无法牵入同步的技术问题。(The invention discloses a control method and a control system for a self-starting synchronous motor, a storage medium and a processor. Wherein, the method comprises the following steps: controlling the self-starting synchronous motor to be electrified and detecting the rotating speed of the self-starting synchronous motor, wherein the rotating speed of the self-starting synchronous motor gradually rises; controlling the input voltage of the self-starting synchronous motor to start rising when the rotating speed of the self-starting synchronous motor reaches a first rotating speed; when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, the input voltage of the self-starting synchronous motor rises to a preset voltage, wherein the first rotating speed is lower than the second rotating speed, the second rotating speed is lower than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is higher than the rated voltage of the self-starting synchronous motor; and controlling the input voltage to be kept at the preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time. The invention solves the technical problem that the self-starting synchronous motor cannot involve synchronization in the starting process.)

1. A control method of a self-starting synchronous motor, characterized by comprising:

controlling the self-starting synchronous motor to be electrified and detecting the rotating speed of the self-starting synchronous motor, wherein the rotating speed of the self-starting synchronous motor gradually rises;

when the rotating speed of the self-starting synchronous motor reaches a first rotating speed, controlling the input voltage of the self-starting synchronous motor to start rising, and when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, the input voltage rises to a preset voltage, wherein the first rotating speed is less than the second rotating speed, the second rotating speed is less than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor;

and controlling the input voltage to be kept at the preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time.

2. The method of claim 1, wherein controlling the self-starting synchronous machine to power up comprises:

acquiring an initial voltage, wherein the initial voltage is less than the rated voltage of the self-starting synchronous motor;

and controlling the self-starting synchronous motor to be electrified by the initial voltage.

3. The method of claim 1, wherein obtaining an initial voltage comprises:

acquiring the ratio of the current starting load to the maximum load of the self-starting synchronous motor under the rated voltage;

determining the product of the ratio and the rated voltage as the initial voltage.

4. The method according to claim 1, wherein the rotation speed of the self-starting synchronous motor fluctuates up and down after the first time of reaching the rated rotation speed, and after controlling the input voltage to be maintained at the preset voltage until the rotation speed of the self-starting synchronous motor reaches the rated rotation speed for the first time, the method further comprises:

controlling the input voltage to drop;

recording the number of times that the rotating speed of the self-starting synchronous motor reaches the rated rotating speed in the process of the reduction of the input voltage;

and when the Nth time of the self-starting synchronous motor reaches the rated rotating speed, controlling the input voltage to drop to the rated voltage and keeping the input voltage, wherein N is an integer greater than 2.

5. The method according to claim 4, characterized in that after controlling the input voltage to drop to the rated voltage and to be maintained when the self-starting synchronous motor reaches the rated rotational speed the nth time, the method further comprises:

detecting whether the rotating speed of the self-starting synchronous motor is within a preset range within preset time;

and if the rotating speed of the self-starting synchronous motor is within the preset range, stopping adjusting the input voltage of the self-starting synchronous motor.

6. The method of claim 1, wherein the second rotational speed is a half speed rated rotational speed.

7. A control system for a self-starting synchronous machine, comprising:

self-starting a synchronous motor;

the rotation speed detection device is used for detecting the rotation speed of the self-starting synchronous motor, wherein the rotation speed of the self-starting synchronous motor gradually rises after being electrified;

the voltage regulating device is connected with the rotating speed detection device and is used for controlling the self-starting synchronous motor to be electrified, controlling the input voltage of the self-starting synchronous motor to start rising when the rotating speed of the self-starting synchronous motor reaches a first rotating speed, and increasing the input voltage to a preset voltage when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, wherein the first rotating speed is less than the second rotating speed, the second rotating speed is less than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor; the voltage regulating device is also used for controlling the input voltage to be kept at the preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time.

8. The system of claim 7, wherein the voltage regulator device is further configured to control the self-starting synchronous machine to power up at an initial voltage, wherein the initial voltage is less than a rated voltage of the self-starting synchronous machine.

9. The system of claim 8, wherein the speed of the self-starting synchronous machine fluctuates up and down after the first time the rated speed is reached, and the voltage regulating device is further configured to control the input voltage to decrease after the first time the speed of the self-starting synchronous machine reaches the rated speed, and to control the input voltage to decrease to the rated voltage and to maintain when the Nth time the self-starting synchronous machine reaches the rated speed, wherein N is an integer greater than 2.

10. The system of claim 7, further comprising:

and the switch is arranged between the rotating speed detection device and the voltage regulation device and is used for being closed after the self-starting synchronous motor is electrified, wherein after the input voltage is controlled to be reduced to the rated voltage and maintained, if the rotating speed of the self-starting synchronous motor is within a preset range, the switch is disconnected.

11. A storage medium characterized by comprising a stored program, wherein a device in which the storage medium is located is controlled to execute the control method of the self-starting synchronous motor according to any one of claims 1 to 6 when the program is executed.

12. A processor, characterized in that the processor is configured to run a program, wherein the program is configured to execute the control method of the self-starting synchronous machine according to any one of claims 1 to 6 when running.

Technical Field

The invention relates to the technical field of self-starting synchronous motor control, in particular to a control method and system of a self-starting synchronous motor, a storage medium and a processor.

Background

The self-starting synchronous motor is a motor which can realize synchronous operation after self-starting through asynchronous torque, can be directly connected with a power supply to realize starting, and does not need to be controlled by a frequency converter in the starting process. However, the starting torque and the pull-in torque of the motor are in a negative correlation rule, and the starting torque of the motor is large in the initial starting stage, so that the motor has large starting current and can generate large influence on a power grid; in the traction synchronization process, the traction torque of the motor is small, so that the situation that the motor cannot be subjected to traction synchronization can occur in the starting process, and the application occasions of the self-starting motor are limited due to the problems that the starting current of the self-starting synchronous motor is large and the motor cannot be subjected to traction synchronization.

Aiming at the technical problem that the self-starting synchronous motor in the prior art cannot involve synchronization in the starting process, an effective solution is not provided at present.

Disclosure of Invention

The embodiment of the invention provides a control method and system of a self-starting synchronous motor, a storage medium and a processor, which are used for at least solving the technical problem that the self-starting synchronous motor in the prior art cannot involve in synchronization in the starting process.

According to an aspect of an embodiment of the present invention, there is provided a control method of a self-starting synchronous motor, including: controlling the self-starting synchronous motor to be electrified and detecting the rotating speed of the self-starting synchronous motor, wherein the rotating speed of the self-starting synchronous motor gradually rises; controlling the input voltage of the self-starting synchronous motor to start rising when the rotating speed of the self-starting synchronous motor reaches a first rotating speed, and controlling the input voltage of the self-starting synchronous motor to rise to a preset voltage when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, wherein the first rotating speed is smaller than the second rotating speed, the second rotating speed is smaller than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is larger than the rated voltage of the self-starting synchronous motor; and controlling the input voltage to be kept at the preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time.

Further, controlling the self-starting synchronous motor to be powered on comprises the following steps: acquiring an initial voltage, wherein the initial voltage is less than the rated voltage of the self-starting synchronous motor; and controlling the self-starting synchronous motor to be electrified by using the initial voltage.

Further, obtaining an initial voltage comprises: acquiring the ratio of the current starting load to the maximum load of the self-starting synchronous motor under the rated voltage; the product of the ratio and the rated voltage is determined as the initial voltage.

Further, the rotation speed of the self-starting synchronous motor fluctuates up and down after the first time of reaching the rated rotation speed, and the method further comprises the following steps of maintaining the control input voltage at the preset voltage until the first time of reaching the rated rotation speed of the self-starting synchronous motor: controlling the input voltage to drop; recording the number of times that the rotating speed of the self-starting synchronous motor reaches the rated rotating speed in the process of input voltage reduction; and when the Nth time of the self-starting synchronous motor reaches the rated rotating speed, controlling the input voltage to be reduced to the rated voltage and keeping the voltage, wherein N is an integer larger than 2.

Further, after controlling the input voltage to drop to the rated voltage and to be maintained when the self-starting synchronous motor reaches the rated rotation speed the nth time, the method further includes: detecting whether the rotating speed of the self-starting synchronous motor is within a preset range within preset time; and if the rotating speed of the self-starting synchronous motor is within the preset range, stopping adjusting the input voltage of the self-starting synchronous motor.

Further, the second rotational speed is a half-speed rated rotational speed.

According to another aspect of the embodiments of the present invention, there is provided a control system of a self-starting synchronous motor, including: self-starting a synchronous motor; the rotation speed detection device detects the rotation speed of the self-starting synchronous motor, wherein the rotation speed of the self-starting synchronous motor gradually rises after being electrified; the voltage regulating device is connected with the rotating speed detection device and used for controlling the self-starting synchronous motor to be electrified, controlling the input voltage of the self-starting synchronous motor to start rising when the rotating speed of the self-starting synchronous motor reaches a first rotating speed, and controlling the input voltage to rise to a preset voltage when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, wherein the first rotating speed is less than the second rotating speed, the second rotating speed is less than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor; the voltage regulating device is also used for controlling the input voltage to be kept at the preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time.

Further, the voltage regulating device is also used for controlling the self-starting synchronous motor to be powered on by using initial voltage, wherein the initial voltage is smaller than the rated voltage of the self-starting synchronous motor.

Further, the rotating speed of the self-starting synchronous motor fluctuates up and down after reaching the rated rotating speed for the first time, the voltage regulating device is further used for controlling the input voltage to drop after the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time, and when the self-starting synchronous motor reaches the rated rotating speed for the Nth time, the input voltage is controlled to drop to the rated voltage and is kept, wherein N is an integer greater than 2.

Further, the above system further comprises: and the switch is arranged between the rotating speed detection device and the voltage regulation device and is closed after the self-starting synchronous motor is electrified, wherein the switch is disconnected if the rotating speed of the self-starting synchronous motor is within a preset range after the input voltage is controlled to be reduced to the rated voltage and kept.

According to another aspect of the embodiments of the present invention, there is provided a storage medium including a stored program, wherein the apparatus on which the storage medium is located is controlled to execute the control method of the self-starting synchronous motor when the program is executed.

According to another aspect of the embodiments of the present invention, there is provided a processor for executing a program, wherein the program executes the control method of the self-starting synchronous motor.

In the embodiment of the invention, the voltages of different rotating speed sections are controlled according to the rotating speed detection result of the self-starting synchronous motor, so that the pull-in synchronization capability of the self-starting synchronous motor is enhanced, and the technical problem that the self-starting synchronous motor cannot be pulled in synchronization due to the negative correlation between the starting torque and the pull-in torque in the starting process is solved. On the other hand, the voltage of the self-starting synchronous motor at the initial starting stage is controlled according to the size of the starting load, so that the starting current of the self-starting synchronous motor at the starting stage is reduced, and the problem of large starting current of the self-starting synchronous motor at the starting stage is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:

fig. 1 is a flowchart of a control method of a self-starting synchronous motor according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an alternative control system for a self-starting synchronous machine according to an embodiment of the present invention;

FIG. 3 is a flow chart of an alternative method of controlling a self-starting synchronous machine according to an embodiment of the present invention;

FIG. 4 is a graph illustrating a variation law of a voltage value of a self-starting synchronous motor according to a control method of an embodiment of the present invention;

FIG. 5 is a graph comparing a control method of an embodiment of the present invention with a prior art speed-time curve during motor starting;

fig. 6 is a schematic diagram of a control system for a self-starting synchronous machine according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Example 1

In accordance with an embodiment of the present invention, there is provided an embodiment of a method for controlling a self-starting synchronous machine, wherein the steps illustrated in the flowchart of the figure may be performed in a computer system, such as a set of computer-executable instructions, and wherein, although a logical order is illustrated in the flowchart, in some cases, the steps illustrated or described may be performed in an order different than that illustrated herein.

Fig. 1 is a control method of a self-starting synchronous motor according to an embodiment of the present invention, as shown in fig. 1, the method including the steps of:

step S101, controlling the self-starting synchronous motor to be electrified and detecting the rotating speed of the self-starting synchronous motor, wherein the rotating speed of the self-starting synchronous motor gradually rises;

step S102, when the rotating speed of the self-starting synchronous motor reaches a first rotating speed, controlling the input voltage of the self-starting synchronous motor to start rising, and when the rotating speed of the self-starting synchronous motor reaches a second rotating speed, the input voltage rises to a preset voltage, wherein the first rotating speed is less than the second rotating speed, the second rotating speed is less than the rated rotating speed of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor;

and step S103, controlling the input voltage to be kept at a preset voltage until the rotating speed of the self-starting synchronous motor reaches the rated rotating speed for the first time.

The self-starting synchronous motor has the self-starting capability, and comprises but is not limited to a self-starting permanent magnet synchronous motor, a self-starting permanent magnet auxiliary synchronous reluctance motor, a self-starting synchronous reluctance motor and other motors which are synchronously operated through self-starting realized by asynchronous torque.

In step S101, the self-starting synchronous motor may be powered up by a voltage regulator disposed in the power supply circuit of the self-starting synchronous motor.

The starting capability of the self-starting synchronous motor is influenced by the input voltage of the self-starting synchronous motor, the larger the input voltage is, the larger the starting torque of the self-starting synchronous motor is, the larger the self-starting synchronous motor can carry a starting load is, the faster the rotating speed of the self-starting synchronous motor rises, and the larger the starting current is; meanwhile, the larger the voltage at the input end of the self-starting synchronous motor is, the larger the pull-in torque of the self-starting synchronous motor is, and the higher the possibility that the self-starting synchronous motor is successfully pulled in synchronization is. Since the starting torque and the pull-in torque of the self-starting synchronous motor are positively correlated with the motor input terminal voltage, in step S102, a preset voltage greater than the rated voltage of the self-starting synchronous motor is set, and the pull-in torque is increased by increasing the input voltage when the self-starting synchronous motor is pulled in synchronization, thereby enhancing the pull-in synchronization capability of the self-starting synchronous motor.

The preset voltage is the maximum value which can be reached by the self-starting synchronous motor in the starting process, and can be set according to the actual starting load and the load inertia condition of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor, so that the self-starting synchronous motor has higher pull-in torque when working under the preset voltage. Optionally, the preset voltage may be set to have a certain margin according to the starting inertia of the self-starting synchronous motor, for example, the preset voltage may be selected to be 1.3 times of the initial voltage when the self-starting synchronous motor is powered on.

The first rotational speed should be less than the rated rotational speed of the self-starting synchronous motor, and the first rotational speed may be set according to the actual detected transmission of the rotational speed signal and the delay of the input voltage adjustment action. Step S102 and step S103 may be understood as that, when the rotation speed of the self-starting synchronous motor is within a range from the first rotation speed to the rated rotation speed (i.e. a range greater than the first rotation speed and less than the rated rotation speed), the input voltage of the self-starting synchronous motor is increased and the self-starting synchronous motor is kept operating at a preset voltage value until the rotation speed of the self-starting synchronous motor is increased to the rated rotation speed, so that the self-starting synchronous motor has a higher input voltage value at a lower rotation speed, and the self-starting synchronous motor is ensured to be able to smoothly pull into. For example, the first rotation speed may be 0.46 times the rated rotation speed, and when the rotation speed of the self-starting synchronous motor is 0.46 times the rated rotation speed, the input voltage starts to rise, and when the rotation speed reaches 0.5 times the rated rotation speed, the input voltage of the self-starting synchronous motor reaches the preset voltage and keeps running at the preset voltage until the rotation speed of the self-starting synchronous motor reaches the rated rotation speed.

In step S103, the input voltage is kept at the preset voltage for operation until the rotation speed of the self-starting synchronous motor is increased to the rated rotation speed, and the preset voltage is kept for operation for a period of time, so that the self-starting synchronous motor can pass through the rotation speed section which is most likely to be out of step in the starting process, and the self-starting synchronous motor can be ensured to be smoothly involved in synchronization.

Through the steps, the voltage values of different rotating speed sections are controlled according to the rotating speed detection result of the self-starting synchronous motor, the self-starting synchronous motor is controlled to have a higher input voltage value at a low rotating speed, the motor can penetrate through the section with the weakest starting rotating speed to be drawn into synchronization, and the starting capability and the drawing synchronization capability of the motor are enhanced.

Optionally, controlling the self-starting synchronous motor to be powered on comprises: acquiring an initial voltage, wherein the initial voltage is less than the rated voltage of the self-starting synchronous motor; and controlling the self-starting synchronous motor to be electrified by using the initial voltage.

Specifically, before the self-starting synchronous motor is started, the input voltage of the self-starting synchronous motor in the initial starting stage is controlled according to the size of an actual starting load, and an initial voltage value smaller than a rated voltage is set for the self-starting synchronous motor so as to reduce the larger starting current of the self-starting synchronous motor in the initial starting stage.

The initial voltage should be kept with a certain margin.

Optionally, obtaining an initial voltage comprises: acquiring the ratio of the current starting load to the maximum load of the self-starting synchronous motor under the rated voltage; the product of the ratio and the rated voltage is determined as the initial voltage.

The initial voltage value U can be calculated according to the following formula:

wherein, T_loadFor the current starting load, T_maxFor maximum load of self-starting synchronous machines at rated voltage, U_NIs the rated voltage of the self-starting synchronous machine.

Optionally, the rotation speed of the self-starting synchronous motor fluctuates up and down after the first time of reaching the rated rotation speed, and after the control input voltage is kept at the preset voltage until the first time of reaching the rated rotation speed of the self-starting synchronous motor, the method further includes: controlling the input voltage to drop; recording the number of times that the rotating speed of the self-starting synchronous motor reaches the rated rotating speed in the process of input voltage reduction; and when the Nth time of the self-starting synchronous motor reaches the rated rotating speed, controlling the input voltage to be reduced to the rated voltage and keeping the voltage, wherein N is an integer larger than 2.

The input voltage of the self-starting synchronous motor is kept to be the preset voltage until the rotating speed of the self-starting synchronous motor is increased to the rated rotating speed, on one hand, the self-starting synchronous motor is enabled to input a larger voltage value at a lower rotating speed so as to ensure that the self-starting synchronous motor can smoothly pull in synchronization, on the other hand, the input voltage value is reduced when the self-starting synchronous motor reaches the rated rotating speed, and when the Nth time (for example, the third time) reaches the rated rotating speed, the input voltage is reduced to the rated voltage and the rated voltage is kept running, so that the rotating speed of the self-starting synchronous motor can be ensured not to generate large fluctuation due to sudden drop of the input voltage, the time of the rotating speed fluctuation of the self-starting synchronous motor can be prevented from being. Since the operating voltage after the self-starting synchronous motor is synchronized is a rated voltage, it is necessary to define both a rotation speed point at which the input voltage stops decreasing and a corresponding input voltage value.

The number N of times that the rotation speed of the self-starting synchronous motor reaches the rated rotation speed may be understood as the minimum number of times that the rotation speed of the self-starting synchronous motor required to be subjected to the reduction of the input voltage of the self-starting synchronous motor from the preset voltage to the rated voltage fluctuates to the rated rotation speed, that is, the rotation speed of the self-starting synchronous motor fluctuates within a range around the rated rotation speed value, and when the nth number of times of the rotation speed of the self-starting synchronous motor is equal to the rated rotation speed, the reduction of the input voltage is stopped, and optionally, the input voltage is maintained at the rated voltage value. The method limits the minimum times of the fluctuation of the corresponding rotating speed to the rated rotating speed when the input voltage of the self-starting synchronous motor is reduced to the rated voltage from the preset voltage, can avoid the large downward depression point of the rotating speed of the self-starting synchronous motor in the pulling synchronization process, considers the overshoot of the rotating speed of the self-starting synchronous motor in the self-starting and rising process and the fluctuation time of the rotating speed of the self-starting synchronous motor after the pulling synchronization, and can adjust according to the actual running environment of the self-starting synchronous motor and the starting load condition.

Optionally, after controlling the input voltage to drop to the rated voltage and to be maintained when the self-starting synchronous motor reaches the rated rotation speed N times, the method further includes: detecting whether the rotating speed of the self-starting synchronous motor is within a preset range within preset time; and if the rotating speed of the self-starting synchronous motor is within the preset range, stopping regulating the input voltage of the self-starting synchronous motor.

The rotation speed of the self-starting synchronous motor is within a preset range, which means that the rotation speed of the self-starting synchronous motor is stable at a synchronous speed, the fluctuation range of the rotation speed is within the preset range, and the self-starting of the self-starting synchronous motor is successful. The preset range of the rotating speed of the self-starting synchronous motor is set according to the actual running environment and the starting load condition of the self-starting synchronous motor, and meanwhile, the fluctuation factor of the power grid voltage needs to be considered, so that the times of starting and stopping the self-starting synchronous motor caused by the unsuccessful starting of the self-starting synchronous motor are reduced as much as possible, and further, the abrasion of a controllable switch for controlling the starting and stopping of the self-starting synchronous motor is reduced.

Optionally, the second speed is a half speed rated speed.

The half-speed rated speed is understood to be half of the rated speed, i.e. 0.5 times the rated speed, which is the weakest speed during the starting process of the self-starting synchronous motor. When the rotating speed of the self-starting synchronous motor is less than the half-speed rated rotating speed, the input voltage starts to rise, and when the rotating speed of the self-starting synchronous motor reaches the half-speed rated rotating speed, the input voltage rises to the preset voltage, so that the capacity of the self-starting synchronous motor for moving into synchronization can be enhanced, and the starting success rate of the self-starting synchronous motor is improved.

According to the steps, the voltages of different rotating speed sections are controlled according to the rotating speed detection result of the self-starting synchronous motor, so that the self-starting synchronous motor has a higher input voltage value at a lower rotating speed, the starting capability and the pull-in synchronization capability of the self-starting synchronous motor are enhanced, and the technical problem that the self-starting synchronous motor cannot be pulled into synchronization due to the fact that the starting torque and the pull-in torque are in negative correlation in the starting process is solved. On the other hand, the voltage of the self-starting synchronous motor at the initial starting stage is controlled according to the size of the starting load, so that the starting current of the self-starting synchronous motor at the starting stage is reduced, and the problem of large starting current of the self-starting synchronous motor at the starting stage is solved.

Fig. 2 is a schematic diagram of an alternative control system of the self-starting synchronous motor according to the embodiment of the present invention, and the control system of the self-starting synchronous motor comprises a self-starting synchronous motor 20, a voltage regulating device 21, a rotating speed detecting device 22, and a controllable switch S1. The self-starting synchronous motor 20 is connected with a rotating speed detection device 22 for detecting the rotating speed value of the self-starting synchronous motor 20 in real time, and meanwhile, the self-starting synchronous motor 20 is connected with a pressure regulating device 21 and receives the signal input of the pressure regulating device 21.

Specifically, in the starting stage of the self-starting synchronous motor, the controllable switch S1 is closed, the self-starting synchronous motor 20, the rotation speed detecting device 22 and the voltage regulating device 21 form a closed-loop control circuit of the starting voltage of the self-starting synchronous motor, and the voltage input value of the self-starting synchronous motor 20 in the starting stage is controlled; after the start is completed, the controllable switch S1 is turned off, and the closed-loop control is exited from the input terminal voltage of the starting synchronous machine 20.

The rotation speed detection device 22 receives a rotation speed signal of the self-starting synchronous motor 20, transmits the rotation speed signal to the pressure regulating device 21, controls the action of the pressure regulating device 21, regulates the input voltage according to the rotation speed change of the self-starting synchronous motor 20, sets a lower initial voltage at the initial starting stage to avoid a large starting current, and sets a larger input voltage at the later starting stage to facilitate the self-starting synchronous motor 20 to be synchronous.

Optionally, a counter is disposed in the rotation speed detecting device 22, and is configured to record the number of synchronous speeds nN (i.e., the number of times that the rotation speed of the self-starting synchronous motor 20 fluctuates to the rated rotation speed nN) of the self-starting synchronous motor 20 detected by the rotation speed detecting device 22, a trigger signal of the counter is the synchronous rotation speed nN of the self-starting synchronous motor 20, an output signal of the counter is transmitted to the pressure regulating device 21, and controls an operation of the pressure regulating device 21, and after the rotation speed of the self-starting synchronous motor 20 reaches the synchronous rotation speed, the output signal of the counter controls the operation of the pressure regulating device 21, so that the self-starting synchronous motor 20 is rapidly stabilized after reaching the synchronous rotation speed, and the fluctuation range of the rotation speed.

The voltage regulating device 21 is a voltage regulating device that can be used to self-start the synchronous motor 20, including but not limited to autotransformers, induction regulators, motor-generator sets. The voltage regulator 21 regulates the voltage based on the received output signal of the rotation speed detector 22, and controls the starting process of the self-starting synchronous motor 20.

The rotating speed detection device and the pressure regulating device can also adopt open-loop control, and the action of the pressure regulating device is manually controlled according to the rotating speed value of the rotating speed detection device, but enough manual regulation time is required to be reserved; in the above embodiment, the control method of the rotation speed detecting device for controlling the operation of the pressure regulating device is not limited.

FIG. 3 is a flow chart of an alternative method of controlling a self-starting synchronous machine according to an embodiment of the present invention; the control method comprises the following steps:

step S301, before the self-starting synchronous motor is started, setting a starting initial voltage value U according to the size of a starting load;

the initial voltage value U can be calculated according to the following formula:

wherein, T_loadFor the current starting load, T_maxFor maximum load of self-starting synchronous machines at rated voltage, U_NIs the rated voltage of the self-starting synchronous machine.

Step S302, closing a controllable switch S1, connecting a starting voltage control loop of the self-starting synchronous motor, and starting the self-starting synchronous motor; keeping the terminal voltage of the self-starting synchronous motor as a starting initial voltage U, and detecting the rotation speed change of the self-starting synchronous motor;

step S303, when the rotating speed of the self-starting synchronous motor rises to 0.46nN, the voltage regulating device acts, and the starting voltage rises; when the rotating speed is increased to 0.5nN, the starting voltage is increased to 1.3U, the voltage regulating device keeps on, and the rotating speed continues to increase.

The rotation speed value of 0.46nN corresponding to the operation point of the pressure regulating device may be set according to the delay characteristics of the rotation speed detecting device and the pressure regulating device which are actually used, in consideration of the delay characteristics of the operations of the rotation speed detecting device and the pressure regulating device. The preset voltage U is set to have a certain margin according to the starting inertia of the self-starting synchronous motor, and can be set according to the actual starting load and the load inertia of the self-starting synchronous motor. Optionally, the preset voltage value is set to range from 1.05U to 1.58U. In an optional embodiment, the initial voltage value of the preset voltage is 1.3 times, so that the self-starting synchronous motor can be ensured to smoothly pass through the weakest starting rotating speed section, and the starting capability and the synchronization involving capability of the self-starting synchronous motor are enhanced.

The nN is the rated rotational speed of the self-starting synchronous motor.

Step S304, when the rotation speed detection device detects that the rotation speed of the self-starting synchronous motor is nN for the first time, the voltage regulation device acts, and the starting voltage begins to drop; when the rotation speed detection device detects that the rotation speed of the self-starting synchronous motor appears for at least the third time nN, the starting voltage is lowerDown to U_NAnd the pressure regulating device keeps the rotating speed to enter a rotating speed fluctuation stage near the synchronous speed.

In step S304, 1.3 times of the starting initial voltage value is maintained until the rotation speed of the motor rises to nN, so that on one hand, the motor can be ensured to be smoothly synchronized, and on the other hand, the rotation speed of the motor cannot generate large fluctuation due to sudden voltage drop, thereby causing damage to a load and a power grid; limiting the start-up voltage from dropping to the rated voltage U_NThe rotating speed detected by the corresponding rotating speed detection module is the minimum number of times of nN, so that the phenomenon that the rotating speed of the motor has a large concave point in the pulling synchronization process can be avoided.

In step S305, when the rotation speed detection means detects that the rotation speed fluctuation of the self-starting synchronous motor is within a certain range within a certain time, the controllable switch S1 is turned off, the start phase of the self-starting synchronous motor is ended, and the synchronous operation state is entered.

The fluctuation range of the rotating speed detected by the rotating speed detection module within a certain time corresponding to the disconnection of the controllable switch S1 is set according to the actual running environment and the starting load condition of the motor, and meanwhile, the fluctuation factor of the power grid voltage needs to be considered, so that the switching times of the controllable switch S1 caused by the unsuccessful starting of the motor are reduced as much as possible, and the abrasion of the switch is reduced.

Fig. 4 is a graph of a variation law of a voltage value of the self-starting synchronous motor obtained by the control method according to the embodiment of the present invention, as shown in fig. 4, where an abscissa is a rotation speed of the self-starting synchronous motor and an ordinate is an input voltage of the self-starting synchronous motor. After the self-starting synchronous motor is powered on, the rotating speed begins to increase. When the rotating speed of the self-starting synchronous motor is between 0 and 0.46nN, the input voltage keeps the starting initial voltage U unchanged until the rotating speed reaches 0.46nN, and the input voltage starts to rise; when the rotating speed of the self-starting synchronous motor is between 0.46nN and 0.5nN, the input voltage continuously rises to 1.3U from the initial voltage U, and the operation of 1.3U is kept; when the speed of the self-starting synchronous motor reaches nN for the first time, the input voltage begins to drop, and when the motor rotatesWhen the speed reaches nN for the third time, the input voltage is reduced to the rated voltage U_NAnd ending the starting stage of the self-starting synchronous motor and entering a synchronous running state, wherein nN is the rated rotating speed of the self-starting synchronous motor. The conversion between different voltage values adopts a gradual change conversion mode, so that the large fluctuation of the rotating speed of the motor caused by sudden voltage change is avoided.

Fig. 5 is a comparison graph of the control method of the embodiment of the present invention and a rotation speed-time curve in the motor starting process of the prior art, wherein the abscissa is the running time of the self-starting synchronous motor since the power-on, and the ordinate is the detected rotation speed. As shown in fig. 5, in the prior art (shown by a dotted line in fig. 5), in the initial stage of starting the self-starting synchronous motor, the starting torque of the self-starting synchronous motor is large, the rotation speed of the self-starting synchronous motor rises quickly, and the starting current is large, so that the self-starting synchronous motor is easy to damage a load and a power grid; in the later stage of starting, the self-starting synchronous motor has low pull-in torque, and the rotating speed of the self-starting synchronous motor fluctuates below the synchronous speed, so that the pull-in synchronization fails. Fig. 5 is a solid line graph of a rotation speed-time curve obtained by the control method according to the embodiment of the present invention, in which the rotation speed of the self-starting synchronous motor is smoothly increased in the initial stage of starting, and the starting current can be limited (large starting current is prevented); after the rotating speed reaches 0.5 times of the rated rotating speed, the rotating speed rising speed of the self-starting synchronous motor is accelerated, and the self-starting synchronous motor is successfully involved in synchronization; after synchronization is involved, the fluctuation time of the rotating speed is short, and the rotating speed is stabilized at the synchronous speed in a short time. Therefore, the pull-in synchronization capacity of the self-starting synchronous motor is enhanced, and the technical problem that the self-starting synchronous motor cannot be pulled in synchronization due to the fact that the starting torque and the pull-in torque are in negative correlation in the starting process is solved.

Example 2

According to an embodiment of the present invention, there is provided an embodiment of a control system for a self-starting synchronous motor, as shown in fig. 6, including: a self-starting synchronous motor 60; a rotation speed detection device 61 that detects a rotation speed of the self-starting synchronous motor 60, wherein the rotation speed of the self-starting synchronous motor 60 gradually rises after being powered on; a voltage regulator 62 connected to the rotation speed detector 61 and configured to control the self-starting synchronous motor 60 to be powered on, and to control the input voltage of the self-starting synchronous motor 60 to start to rise when the rotation speed of the self-starting synchronous motor 60 reaches a first rotation speed, and to rise to a preset voltage when the rotation speed of the self-starting synchronous motor reaches a second rotation speed, where the first rotation speed is less than the second rotation speed, the second rotation speed is less than the rated rotation speed of the self-starting synchronous motor, and the preset voltage is greater than the rated voltage of the self-starting synchronous motor; the voltage regulating device 62 is also used to control the input voltage to be maintained at a preset voltage until the rotation speed of the self-starting synchronous motor 60 reaches the rated rotation speed for the first time.

Optionally, the voltage regulating device 62 is further configured to control the self-starting synchronous motor to be powered up at an initial voltage, where the initial voltage is smaller than a rated voltage of the self-starting synchronous motor.

Optionally, the rotation speed of the self-starting synchronous motor fluctuates up and down after the rotation speed of the self-starting synchronous motor reaches the rated rotation speed for the first time, and the voltage regulating device 62 is further configured to control the input voltage to decrease after the rotation speed of the self-starting synchronous motor reaches the rated rotation speed for the first time, and control the input voltage to decrease to the rated voltage and maintain when the self-starting synchronous motor reaches the rated rotation speed for the nth time, where N is an integer greater than 2.

Optionally, the system further includes: and the switch is arranged between the rotating speed detection device and the voltage regulation device and is closed after the self-starting synchronous motor is electrified, wherein the switch is disconnected if the rotating speed of the self-starting synchronous motor is within a preset range after the input voltage is controlled to be reduced to the rated voltage and kept.

According to an embodiment of the present invention, there is provided a storage medium including a stored program, wherein a device on which the storage medium is located is controlled to execute the control method of the self-starting synchronous motor when the program runs.

According to an embodiment of the present invention, a processor is provided for running a program, wherein the program executes the control method for the self-starting synchronous motor.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

In the above embodiments of the present invention, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, units or modules, and may be in an electrical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.