WO2021174737A1

WO2021174737A1 - Motor control method, motor control apparatus, motor system, and storage medium

Info

Publication number: WO2021174737A1
Application number: PCT/CN2020/100468
Authority: WO
Inventors: 陈辉; 秦向南; 缪周; 付俊永
Original assignee: 广东威灵电机制造有限公司; 美的威灵电机技术（上海）有限公司
Priority date: 2020-03-02
Filing date: 2020-07-06
Publication date: 2021-09-10
Also published as: CN113346804A; CN113346804B

Abstract

The present application provides a motor control method, a motor control apparatus, a motor system, and a storage medium. The motor control method comprises: obtaining a busbar voltage of a motor; and determining that the busbar voltage is greater than a first voltage threshold or the busbar voltage is less than a second voltage threshold, and controlling a switch tube of an intelligent power module of the motor according to the busbar voltage and a voltage instruction value so as to shut down the motor, wherein the first voltage threshold is greater than the second voltage threshold. According to the technical solution of the present application, the motor can be reliably shut down by means of the busbar voltage control in the case of an overvoltage, undervoltage or power-off busbar voltage fault, which avoids the damage to a controller or the motor in the case of the busbar voltage fault, and eliminates the motor stuck sound under the power-off fault, and the use effect is good.

Description

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

This application claims the priority of a Chinese patent application filed to the State Intellectual Property Office of China on March 02, 2020 with the application number "2020101347950" and the application title "Motor control method, motor control device, motor system and storage medium" , Its entire content is incorporated into this application by reference.

Technical field

This application relates to the field of motor technology, and in particular, to a motor control method, a motor control device, a motor system, and a computer-readable storage medium.

Background technique

In the permanent magnet synchronous motor control system, the bus voltage is usually the DC voltage obtained from the AC voltage of the AC grid through the full bridge rectifier circuit and the bus capacitor rectification. The bus voltage is generally used to supply power to the intelligent power (IPM) module to maintain the motor normal Operation; even in low-cost controllers, the control power on the controller is also obtained by the conversion of the bus voltage, so the bus voltage is very important in the entire permanent magnet synchronous motor control system.

In order to ensure the reliability of the entire motor control system, the corresponding overvoltage protection voltage value and undervoltage protection voltage value are usually set in the motor control program to judge whether the bus voltage is too large (referred to as overvoltage) and the bus voltage is too small (referred to as undervoltage) ) Failure, and control the motor to stop when the bus voltage failure occurs.

Power failure on the AC grid side is a special bus voltage failure, referred to as power failure. Compared with over-voltage or under-voltage faults, the bus voltage in the event of a power failure needs to provide the voltage required to control the motor, and even provide the power supply voltage of the entire controller, so the bus voltage is difficult to maintain for a long time. In a motor system with a large load inertia and a high speed, when the power failure occurs, the bus voltage drops to zero and the motor has not decelerated to stop. The motor will be in a state of out of control, especially if manual work with the whole system is required. In the case of operation, the damage of power failure is more serious.

In the power failure handling method of the related technology, the bus voltage will fluctuate greatly, and the greater bus voltage fluctuation will lead to a larger ripple current, and the service life of the capacitor will also be affected by the increase of the ripple current. Significantly shortened, it will affect the life cycle of the entire controller. In addition, in the power failure handling methods of related technologies, the commonly used methods are to switch off all the upper and lower arm switch tubes of the IPM module, all the lower bridge arm switch tubes, and all the upper and lower arm switch tubes of the IPM module are switched off. , It will cause the motor to switch back and forth between the controlled and free-running states. Due to the switching frequency of the two actions, the sound of the motor stalling will be produced in the whole machine system, and a good user experience will be lost.

Summary of the invention

This application aims to solve at least one of the technical problems existing in the prior art or related technologies.

To this end, one aspect of the present application is to propose a motor control method.

Another aspect of the present application is to provide a motor control device.

Another aspect of the present application is to propose a motor system.

Another aspect of the present application is to provide a computer-readable storage medium.

In view of this, according to one aspect of the application, a motor control method is proposed, including: obtaining the bus voltage of the motor; determining that the bus voltage is greater than a first voltage threshold or the bus voltage is less than a second voltage threshold, according to the bus voltage and the voltage command Value, which controls the switch tube of the intelligent power module of the motor to stop the motor, wherein the first voltage threshold is greater than the second voltage threshold.

The motor control method provided in this application judges whether a bus voltage failure occurs based on the current bus voltage, the overvoltage protection voltage value (first voltage threshold), and the undervoltage protection voltage value (second voltage threshold). When the voltage value of voltage protection or less than the voltage value of undervoltage protection, it indicates that there is a bus voltage failure, otherwise there is no failure. In the case of a bus voltage failure, the voltage command value is selected, and then the switch tube of the IPM module is controlled to turn on or off, and the bus voltage is controlled near the voltage command value to realize the motor shutdown. With the technical solution of the present application, in the event of overvoltage, undervoltage or power failure (the busbar voltage is less than the second voltage threshold at the time of power failure) bus voltage failure, the motor can be reliably shut down through bus voltage control to avoid bus voltage failure. It will cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

According to the above-mentioned motor control method of the present application, it may also have the following technical features:

In the above technical solution, determining that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and according to the bus voltage and the voltage command value, the step of controlling the switch tube of the intelligent power module of the motor includes: determining that the bus voltage is greater than The first voltage threshold or the bus voltage is less than the second voltage threshold, the voltage command value is selected; the upper-side switch tube of the intelligent power module is controlled to be turned off, and the lower bridge of the intelligent power module is controlled according to the difference between the voltage command value and the bus voltage Arm switch tube.

In this technical solution, the control signal of the upper arm switch tube of the IPM module has nothing to do with the bus voltage error (the difference between the voltage command value and the bus voltage), and the duty ratio of the control signal that controls the upper arm switch tube of the IPM module is always 0, that is, the upper switch tube of the IPM module is always off. According to the bus voltage error, the control signal of the lower arm switch tube of the IPM module is obtained, and the duty ratio of the control signal is dynamically adjusted with the bus voltage error. The bus voltage is controlled near the voltage command value to realize the motor shutdown to avoid the motor During the shutdown process, the large ripple current appears due to the large fluctuation of the bus voltage, which reduces the life of the controller.

In any of the above technical solutions, according to the difference between the voltage command value and the bus voltage, the step of controlling the switch tube of the lower arm of the intelligent power module specifically includes: the difference is greater than 0, and the control is controlled according to the increase in the absolute value of the difference. The duty cycle of the signal decreases, or the difference is less than 0, the duty cycle of the control signal increases according to the increase in the absolute value of the difference; the lower-arm switch tube of the intelligent power module is controlled according to the duty cycle of the control signal, The control signal is that the lower-arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower-arm switch tube of the low-level intelligent power module is turned off.

In this technical solution, when the bus voltage error is greater than zero and as the absolute value of the bus voltage error increases, the duty cycle of the control signals of all the switching tubes of the lower bridge arm of the IPM module decreases; when the bus voltage error is less than zero and With the increase of the absolute value of the bus voltage error, the duty ratio of the control signal of all switch tubes controlling the lower bridge arm of the IPM module increases, thereby eliminating the steady-state error of the command bus voltage and the feedback bus voltage. Among them, the duty cycle represents the ratio of the time that the control signal is at a high level to the entire control cycle. The low level of the control signal represents that the switch tube that controls the IPM module is turned off, and the high level of the control signal represents the switch tube that controls the IPM module. Open. The technical solution of the present application can realize the reliable shutdown of the motor only by controlling the bus voltage, without the need for signals such as voltage, current, or position, to achieve accurate current control, and this method is suitable for bus voltage faults such as overvoltage, undervoltage, and power failure. It is easy to implement and has strong robustness and reliability. In addition, using the method provided in this application to perform the motor shutdown action can keep the bus voltage stable and increase the service life of the bus capacitor; eliminate the sound of the motor stuck in the power failure, and the user experience is better.

In any of the above technical solutions, the step of selecting the voltage command value specifically includes: the bus voltage is greater than the first voltage threshold, and the first voltage threshold is used as the voltage command value; the bus voltage is less than the second voltage threshold, and the third voltage threshold is used as the voltage command value. The voltage command value, and the third voltage threshold is the rectified AC grid voltage.

In this technical solution, when a bus voltage failure occurs, when the bus voltage is greater than the overvoltage protection voltage value, the overvoltage protection voltage value is selected as the voltage command value to avoid causing the bus voltage to overvoltage; when the bus voltage is less than the undervoltage protection voltage When the value is selected, the normal working bus voltage value (the third voltage threshold) is selected as the voltage command value. The normal working bus voltage value is obtained from the AC voltage of the AC grid through the full-bridge rectifier circuit and the bus capacitor rectification. If the normal working bus voltage value is selected The voltage command value can make the voltage on the bus capacitor more stable, which is beneficial to prolong the service life of the capacitor.

In any of the above technical solutions, the step of selecting the voltage command value specifically includes: selecting any value within a preset value range as the voltage command value, wherein the preset value range is greater than or equal to the minimum value of the system operating voltage and less than Or equal to the first voltage threshold.

In this technical solution, when a bus voltage failure occurs, any voltage value between the overvoltage protection voltage value and the minimum voltage value that can maintain the operation of the motor drive system can be selected as the voltage command value (including the overvoltage protection voltage value and Minimum voltage value), so as to avoid causing overvoltage on the busbar voltage, and at the same time to ensure the normal operation of the system.

According to another aspect of the present application, a motor control device is proposed, which includes: a voltage sampler for obtaining the bus voltage of the motor; a memory, which stores a computer program; a processor, which implements when the processor executes the computer program: Determine that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, according to the bus voltage and the voltage command value, control the switch tube of the intelligent power module of the motor to stop the motor, wherein the first voltage threshold is greater than the second voltage threshold .

The motor control device provided in this application judges whether a bus voltage failure occurs based on the current bus voltage, the overvoltage protection voltage value (first voltage threshold), and the undervoltage protection voltage value (second voltage threshold). When the voltage value of voltage protection or less than the voltage value of undervoltage protection, it indicates that there is a bus voltage failure, otherwise there is no failure. In the case of a bus voltage failure, the voltage command value is selected, and then the switch tube of the IPM module is controlled to turn on or off, and the bus voltage is controlled near the voltage command value to realize the motor shutdown. With the technical solution of the present application, in the event of overvoltage, undervoltage or power failure (the busbar voltage is less than the second voltage threshold at the time of power failure) bus voltage failure, the motor can be reliably shut down through bus voltage control to avoid bus voltage failure. It will cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

The above-mentioned motor control device according to the present application may also have the following technical features:

In the above technical solution, the processor executes the step of determining that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and controlling the switch tube of the intelligent power module of the motor according to the bus voltage and the voltage command value, which specifically includes: determining If the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, select the voltage command value; control the upper arm switch tube of the smart power module to turn off, and control the smart power module according to the difference between the voltage command value and the bus voltage The lower bridge arm switch tube.

In any of the above technical solutions, the processor executes the step of controlling the switch tube of the lower arm of the intelligent power module according to the difference between the voltage command value and the bus voltage, which specifically includes: the difference is greater than 0, and the difference is determined according to the absolute value of the difference. Increase the duty cycle of the control signal to decrease, or the difference is less than 0, increase the duty cycle of the control signal according to the increase in the absolute value of the difference; control the lower arm of the intelligent power module according to the duty cycle of the control signal The switch tube, where the control signal is that the lower-arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower-arm switch tube of the low-level intelligent power module is turned off.

In this technical solution, when the bus voltage error is greater than zero and as the absolute value of the bus voltage error increases, the duty cycle of the control signals of all the switching tubes of the lower bridge arm of the IPM module decreases; when the bus voltage error is less than zero and With the increase of the absolute value of the bus voltage error, the duty ratio of the control signal of all switch tubes controlling the lower bridge arm of the IPM module increases, thereby eliminating the steady-state error of the command bus voltage and the feedback bus voltage. Among them, the duty cycle indicates the ratio of the time the control signal is at a high level to the entire control cycle, the low level of the control signal indicates that the switch tube that controls the IPM module is turned off, and the high level of the control signal indicates that the switch tube that controls the IPM module is turned off. Open. The technical solution of the present application can realize the reliable shutdown of the motor only by controlling the bus voltage, without the need for signals such as voltage, current, or position, to achieve accurate current control, and this method is suitable for bus voltage faults such as overvoltage, undervoltage, and power failure. It is easy to implement and has strong robustness and reliability. In addition, using the method provided in this application to perform the motor shutdown action can keep the bus voltage stable and increase the service life of the bus capacitor; eliminate the sound of the motor stuck in the power failure, and the user experience is better.

In any of the above technical solutions, the processor executes the step of selecting the voltage command value, which specifically includes: the bus voltage is greater than the first voltage threshold, and the first voltage threshold is used as the voltage command value; the bus voltage is less than the second voltage threshold, and the third The voltage threshold is used as the voltage command value, and the third voltage threshold is the rectified AC grid voltage.

In any of the above technical solutions, the processor executes the step of selecting the voltage command value, which specifically includes: selecting any value within a preset value range as the voltage command value, wherein the preset value range is greater than or equal to the minimum value of the system operating voltage Value and less than or equal to the first voltage threshold.

According to another aspect of the present application, a motor system is proposed, including: a motor; and a motor control device such as any one of the above technical solutions.

The motor system provided by this application includes the motor and the motor control device of any of the above technical solutions. In the case of a bus voltage failure of the motor, the motor control device controls the switching tube of the IPM module to turn on or off, and the bus voltage is controlled at the voltage Near the command value, the motor stops. With the technical solution of the present application, in the event of overvoltage, undervoltage or power failure (the busbar voltage is less than the second voltage threshold at the time of power failure) bus voltage failure, the motor can be reliably shut down through bus voltage control to avoid bus voltage failure. It will cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

According to another aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, a motor control method such as any one of the above technical solutions is implemented.

The computer-readable storage medium provided in the present application implements the steps of the motor control method of any of the above technical solutions when the computer program is executed by the processor. Therefore, the computer-readable storage medium includes all of the motor control methods of any of the above technical solutions. Beneficial effect.

The additional aspects and advantages of the present application will become apparent in the following description, or be understood through the practice of the present application.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Fig. 1 shows a schematic flowchart of a motor control method according to a first embodiment of the present application;

Fig. 2 shows a schematic flowchart of a motor control method according to a second embodiment of the present application;

Fig. 3 shows a schematic flowchart of a motor control method according to a third embodiment of the present application;

Fig. 4 shows a logic block diagram of bus voltage control according to an embodiment of the present application;

FIG. 5 shows a schematic flowchart of a motor control method according to a fourth embodiment of the present application;

FIG. 6 shows a schematic flowchart of determining a bus voltage failure according to an embodiment of the present application;

FIG. 7 shows a schematic diagram of the process of selecting a command bus voltage value according to an embodiment of the present application;

FIG. 8 shows a control logic block diagram of a voltage regulator according to an embodiment of the present application;

FIG. 9 shows a schematic diagram of a voltage waveform of a power-down fault shutdown bus in an embodiment of the present application;

Fig. 10 shows a schematic block diagram of a motor control device according to an embodiment of the present application;

Fig. 11 shows a schematic block diagram of a motor system according to an embodiment of the present application.

Detailed ways

In order to be able to understand the above objectives, features and advantages of the application more clearly, the application will be further described in detail below with reference to the accompanying drawings and specific implementations. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other if there is no conflict.

In the following description, many specific details are set forth in order to fully understand this application. However, this application can also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific details disclosed below. Limitations of the embodiment.

The embodiment of the first aspect of the present application proposes a motor control method, and the motor control method is described in detail through the following embodiments.

Embodiment 1. Fig. 1 shows a schematic flowchart of a motor control method according to a first embodiment of the present application. Among them, the method includes:

Step 102: Obtain the bus voltage of the motor;

Step 104: Determine that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and control the switch tube of the intelligent power module of the motor according to the bus voltage and the voltage command value to stop the motor. The first voltage threshold is greater than the first voltage threshold. 2. Voltage threshold.

The motor control method provided in this application judges whether a bus voltage failure occurs based on the current bus voltage, the overvoltage protection voltage value (first voltage threshold), and the undervoltage protection voltage value (second voltage threshold). When the voltage value of voltage protection or less than the voltage value of undervoltage protection, it indicates that there is a bus voltage failure, otherwise there is no failure. In the case of a bus voltage failure, the voltage command value is selected, and then the switch tube of the IPM module is controlled to turn on or off, and the bus voltage is controlled near the voltage command value to realize the motor shutdown. Through the embodiments of the present application, in the case of overvoltage, undervoltage or power failure (when the power is off, the bus voltage is less than the second voltage threshold) bus voltage failure, the motor can be reliably stopped through the bus voltage control, and the bus voltage failure can be avoided. It will cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

In some embodiments, when the bus voltage is between the undervoltage protection voltage value and the overvoltage protection voltage value, there is no bus voltage failure, and the normal motor operation procedure is executed.

In some embodiments, the overvoltage protection voltage value and the undervoltage protection voltage value can be set by the user according to the actual working conditions of the control system. For example, the overvoltage protection voltage value is determined by the minimum withstand voltage value of the rectifier capacitor and the IPM module switch tube. The value of the under-voltage protection voltage is determined by the minimum voltage that can maintain the normal operation of the entire system.

In the above embodiment, in step 104, it is determined that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and according to the bus voltage and the voltage command value, the switch tube of the intelligent power module of the motor is controlled, which specifically includes: determining the bus If the voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, select the voltage command value; control the upper arm switch of the intelligent power module to turn off, and control the intelligent power module according to the difference between the voltage command value and the bus voltage Lower bridge arm switch tube.

In this embodiment, the control signal of the upper arm switch tube of the IPM module has nothing to do with the bus voltage error (the difference between the voltage command value and the bus voltage), and the duty ratio of the control signal controlling the upper arm switch tube of the IPM module is always 0, that is, the upper switch tube of the IPM module is always off. According to the bus voltage error, the control signal of the lower arm switch tube of the IPM module is obtained, and the duty ratio of the control signal is dynamically adjusted with the bus voltage error. The bus voltage is controlled near the voltage command value to realize the motor shutdown to avoid the motor During the shutdown process, the large ripple current appears due to the large fluctuation of the bus voltage, which reduces the life of the controller.

In any of the above embodiments, the step of controlling the lower-arm switch tube of the intelligent power module according to the difference between the voltage command value and the bus voltage includes: the difference is greater than 0, and the control is controlled according to the increase in the absolute value of the difference. The duty cycle of the signal decreases, or the difference is less than 0, the duty cycle of the control signal increases according to the increase in the absolute value of the difference; the lower-arm switch tube of the intelligent power module is controlled according to the duty cycle of the control signal, The control signal is that the lower-arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower-arm switch tube of the low-level intelligent power module is turned off.

In this embodiment, when the bus voltage error is greater than zero and as the absolute value of the bus voltage error increases, the duty cycle of the control signals that control all the switching tubes of the lower bridge arm of the IPM module decreases; when the bus voltage error is less than zero and With the increase of the absolute value of the bus voltage error, the duty ratio of the control signal of all switch tubes controlling the lower bridge arm of the IPM module increases, thereby eliminating the steady-state error of the command bus voltage and the feedback bus voltage. Among them, the duty cycle represents the ratio of the time that the control signal is at a high level to the entire control cycle. The low level of the control signal represents that the switch tube that controls the IPM module is turned off, and the high level of the control signal represents the switch tube that controls the IPM module. Open. In the embodiment of the present application, reliable shutdown of the motor can be realized by only performing bus voltage control, and accurate current control is achieved without signals such as voltage, current, or position. This method is applicable to bus voltage faults such as overvoltage, undervoltage, and power failure. It is easy to implement and has strong robustness and reliability. In addition, using the method provided in this application to perform the motor shutdown action can keep the bus voltage stable and improve the service life of the bus capacitor; eliminate the sound of the motor stuck in the power failure, and the user experience is better.

In some embodiments, the control signal of the lower arm switch tube of the IPM module is related to the error of the bus voltage, and the duty cycle of the control signal needs to be dynamically adjusted with the error of the bus voltage. Commonly used controllers can use PI (Proportional Integral ) Controller, the single usable controller is not limited to the PI controller. It needs to meet the following characteristics: (1) When the bus voltage error is greater than zero and with the increase of the absolute value of the bus voltage error, it controls the control of all switch tubes of the lower bridge arm of the IPM module. The duty cycle of the control signal decreases; (2) When the bus voltage error is less than zero and with the increase in the absolute value of the bus voltage error, the duty cycle of the control signal that controls all the switch tubes of the lower bridge arm of the IPM module increases; (3) It can eliminate the error between the voltage command value and the bus voltage.

Second embodiment, FIG. 2 shows a schematic flowchart of a motor control method according to a second embodiment of the present application. Among them, the method includes:

Step 202: Obtain the bus voltage of the motor;

Step 204: Determine that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and based on the bus voltage being greater than the first voltage threshold, use the first voltage threshold as the voltage command value, or based on the bus voltage being less than the second voltage threshold, The third voltage threshold is used as the voltage command value, and the third voltage threshold is the rectified AC grid voltage, wherein the first voltage threshold is greater than the second voltage threshold;

Step 206: Control the upper arm switch tube of the intelligent power module to turn off, and control the lower arm switch tube of the intelligent power module according to the difference between the voltage command value and the bus voltage to stop the motor.

In this embodiment, when a busbar voltage failure occurs, when the busbar voltage is greater than the overvoltage protection voltage value, the overvoltage protection voltage value is selected as the voltage command value to avoid causing the busbar voltage to overvoltage; when the busbar voltage is less than the undervoltage protection voltage When the value is selected, the normal working bus voltage value (the third voltage threshold) is selected as the voltage command value. The normal working bus voltage value is obtained from the AC voltage of the AC grid through the full-bridge rectifier circuit and the bus capacitor rectification. If the normal working bus voltage value is selected The voltage command value can make the voltage on the bus capacitor more stable, which is beneficial to prolong the service life of the capacitor.

In the above embodiment, in step 206, the step of controlling the switch tube of the lower arm of the smart power module according to the difference between the voltage command value and the bus voltage, specifically includes: the difference is greater than 0, and the difference is increased according to the absolute value of the difference. The duty cycle of the ambassador control signal decreases, or the difference is less than 0, the duty cycle of the control signal increases according to the increase in the absolute value of the difference; the lower arm switch of the intelligent power module is controlled according to the duty cycle of the control signal The control signal is that the lower-arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower-arm switch tube of the low-level intelligent power module is turned off.

Third embodiment, FIG. 3 shows a schematic flowchart of a motor control method according to a third embodiment of the present application. Among them, the method includes:

Step 302: Obtain the bus voltage of the motor;

Step 304: Determine that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and select any value within the preset value range as the voltage command value, where the first voltage threshold is greater than the second voltage threshold and the preset value range Is greater than or equal to the minimum value of the system operating voltage and less than or equal to the first voltage threshold;

Step 306: Control the upper arm switch tube of the intelligent power module to turn off, and control the lower arm switch tube of the intelligent power module according to the difference between the voltage command value and the bus voltage to stop the motor.

In this embodiment, when a bus voltage failure occurs, any voltage value between the overvoltage protection voltage value and the minimum voltage value that can maintain the operation of the motor drive system can be selected as the voltage command value (including the overvoltage protection voltage value and Minimum voltage value), so as to avoid causing overvoltage on the busbar voltage, and at the same time to ensure the normal operation of the system.

In the above embodiment, in step 306, the step of controlling the switch tube of the lower arm of the smart power module according to the difference between the voltage command value and the bus voltage includes: the difference is greater than 0, and the increase according to the absolute value of the difference The duty cycle of the ambassador control signal decreases, or the difference is less than 0, the duty cycle of the control signal increases according to the increase in the absolute value of the difference; the lower arm switch of the intelligent power module is controlled according to the duty cycle of the control signal The control signal is that the lower-arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower-arm switch tube of the low-level intelligent power module is turned off.

The fourth embodiment, as shown in Figure 4, in the event of a voltage failure (power failure in this embodiment), the current bus voltage detected in real time is based on the current bus voltage and the command bus voltage value (that is, the above voltage command value) Voltage error, the control signal of the switch tube of the IPM module is output through the voltage regulator, and the switch tube of the IPM module is controlled to turn on or off according to the control signal, and the current bus voltage is controlled near the commanded bus voltage value to realize the motor shutdown. As shown in Figure 5, it is mainly divided into the following steps:

Step 502: Compare the current bus voltage with the overvoltage protection voltage value and the undervoltage protection voltage value to determine whether a bus voltage failure occurs. The process of judging whether the bus voltage is faulty is shown in Figure 6. It is judged whether the current bus voltage is greater than the overvoltage protection voltage value, if it is greater than the bus voltage is determined to be faulty, if it is not greater than, continue to determine whether the current bus voltage is less than the undervoltage protection voltage value. If it is less than the bus voltage is determined to be faulty, if it is not less than it is determined that the bus voltage is not faulty.

In step 504, a bus voltage failure occurs, and the command bus voltage value is selected.

Command bus voltage value option one, as shown in Figure 7, after a bus voltage failure, judge whether the current bus voltage is greater than the overvoltage protection voltage value, if it is greater, select the overvoltage protection voltage value as the command bus voltage value; if If it is not greater than, the normal working bus voltage value is selected as the command bus voltage value, and then the bus voltage control is performed until the motor stops. The normal working bus voltage value is obtained from the AC voltage of the AC power grid through the full bridge rectifier circuit and the bus capacitor rectification. In the case of power failure, the bus voltage drops to the undervoltage protection voltage value and the bus voltage failure occurs, and the normal working bus voltage value is selected as the command bus voltage value.

The second option of the commanded bus voltage value is that when a bus voltage failure occurs, any voltage value between the overvoltage protection voltage value and the minimum voltage value that can maintain the operation of the motor drive system is selected as the commanded bus voltage value (including the overvoltage protection voltage). Value and minimum voltage value).

Step 506: Control the switching on or off of the switch tube of the IPM module according to the bus voltage error between the current bus voltage value and the command bus voltage value, and control the current bus voltage near the command bus voltage value to realize the motor shutdown. As shown in Figure 4, the bus voltage error between the current bus voltage value and the command bus voltage value is used as the input signal of the voltage regulator, and the voltage regulator controls the switch tube of the IPM module to turn on or off according to the bus voltage error.

In the event of a power failure, if the current bus voltage drops to the undervoltage protection voltage value and a bus voltage failure occurs, the program will execute the bus voltage control logic to maintain the bus voltage near the normal operating voltage value.

The specific implementation of the voltage regulator in Figure 4 is shown in Figure 8. The control signal of the upper bridge arm switch tube of the IPM module: the duty cycle of the control signal is always 0, that is, all the upper bridge arms of the IPM module are controlled to turn off . The control signal of the switch tube of the lower bridge arm of the IPM module: the duty cycle of the control signal is dynamically adjusted with the error of the bus voltage, specifically: when the bus voltage error is greater than zero and as the absolute value of the bus voltage error increases, the voltage regulator controls The duty cycle of the control signals of all switch tubes in the lower arm of the IPM module is reduced; when the bus voltage error is less than zero and as the absolute value of the bus voltage error increases, the voltage regulator controls the control signals of all the switch tubes in the lower arm of the IPM module The duty cycle increases.

The schematic diagram of the bus voltage waveform diagram of the power failure shutdown bus is shown in Figure 9. Before point A, the power failure has occurred but the controller still has residual power. The current bus voltage can be controlled near the commanded bus voltage value until the motor stops (ie point A). Later).

Finally, when the back EMF of the permanent magnet synchronous motor is always lower than the command bus voltage, the voltage regulator will control all the switch tubes of the upper and lower bridge arms of the IPM module to turn off until the permanent magnet synchronous motor stops.

The embodiment of the second aspect of the present application proposes a motor control device. FIG. 10 shows a schematic block diagram of the motor control device 100 according to an embodiment of the present application. Wherein, the motor control device 100 includes:

The voltage sampler 102 is used to obtain the bus voltage of the motor;

The memory 104 is used for storing computer programs;

When the processor 106 executes a computer program, the processor 106 determines that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and according to the bus voltage and the voltage command value, the switch tube of the intelligent power module of the motor is controlled to make The motor is stopped, where the first voltage threshold is greater than the second voltage threshold.

The motor control device 100 provided in the present application judges whether a bus voltage failure occurs based on the current bus voltage, the overvoltage protection voltage value (first voltage threshold), and the undervoltage protection voltage value (second voltage threshold). When the bus voltage is greater than When the over-voltage protection voltage value or is less than the under-voltage protection voltage value, it indicates that there is a bus voltage failure, otherwise there is no failure. In the case of a bus voltage failure, the voltage command value is selected, and then the switch tube of the IPM module is controlled to turn on or off, and the bus voltage is controlled near the voltage command value to realize the motor shutdown. Through the embodiments of the present application, in the event of overvoltage, undervoltage, or power failure (when the power is off, the bus voltage is less than the second voltage threshold) bus voltage failure, the motor can be reliably shut down through the bus voltage control to avoid bus voltage failure. It can cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

In the foregoing embodiment, the processor 106 executes the step of determining that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and controlling the switch tube of the intelligent power module of the motor according to the bus voltage and the voltage command value, which specifically includes: Determine that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, select the voltage command value; control the upper-side switch tube of the smart power module to turn off, and control the smart power according to the difference between the voltage command value and the bus voltage The lower arm switch tube of the module.

In any of the above embodiments, the processor 106 executes the step of controlling the switch tube of the lower arm of the intelligent power module according to the difference between the voltage command value and the bus voltage, which specifically includes: the difference is greater than 0, and the difference is based on the absolute value of the difference. The increase of, the duty cycle of the control signal is reduced, or the difference is less than 0, the duty cycle of the control signal is increased according to the increase of the absolute value of the difference; the lower bridge of the intelligent power module is controlled according to the duty cycle of the control signal The arm switch tube, where the control signal is that the lower bridge arm switch tube of the high-level intelligent power module is turned on, and the control signal is that the lower bridge arm switch tube of the low-level intelligent power module is turned off.

In this embodiment, when the bus voltage error is greater than zero and as the absolute value of the bus voltage error increases, the duty cycle of the control signals that control all the switching tubes of the lower bridge arm of the IPM module decreases; when the bus voltage error is less than zero and With the increase of the absolute value of the bus voltage error, the duty cycle of the control signal of all switch tubes controlling the lower bridge arm of the IPM module increases, so as to eliminate the steady-state error of the command bus voltage and the feedback bus voltage. Among them, the duty cycle represents the ratio of the time that the control signal is at a high level to the entire control cycle, the low level of the control signal represents that the switch tube that controls the IPM module is turned off, and the high level of the control signal represents the switch tube that controls the IPM module. Open. In the embodiments of the present application, reliable shutdown of the motor can be achieved by only performing bus voltage control, and accurate current control is achieved without signals such as voltage, current, or position. This method is applicable to bus voltage faults such as overvoltage, undervoltage, and power failure. It is easy to implement and has strong robustness and reliability. In addition, the use of the method provided in this application to perform the motor shutdown action can keep the bus voltage stable and improve the service life of the bus capacitor; eliminate the sound of the motor stuck in the power failure, and the user experience is better.

In any of the above embodiments, the processor 106 performs the step of selecting the voltage command value, which specifically includes: the bus voltage is greater than the first voltage threshold, and the first voltage threshold is used as the voltage command value; the bus voltage is less than the second voltage threshold, and the first voltage threshold is used as the voltage command value; The third voltage threshold is used as the voltage command value, and the third voltage threshold is the rectified AC grid voltage.

In any of the above embodiments, the processor executes the step of selecting the voltage command value, which specifically includes: selecting any value within a preset value range as the voltage command value, wherein the preset value range is greater than or equal to the minimum value of the system operating voltage Value and less than or equal to the first voltage threshold.

The embodiment of the third aspect of the present application proposes a motor system. FIG. 11 shows a schematic block diagram of the motor system 200 according to an embodiment of the present application. Among them, the motor system 200 includes:

Motor 202;

Such as the motor control device 100 of any of the above embodiments.

The motor system 200 provided in the present application includes a motor 202 and the motor control device 100 of any of the above embodiments. In the case of a bus voltage failure of the motor, the motor control device controls the switching tube of the IPM module to turn on or off, and the bus voltage It is controlled near the voltage command value to realize the motor shutdown. With the technical solution of the present application, in the event of overvoltage, undervoltage or power failure (the busbar voltage is less than the second voltage threshold at the time of power failure) bus voltage failure, the motor can be reliably shut down through bus voltage control to avoid bus voltage failure. It will cause damage to the controller or the motor at time, and eliminate the sound of the motor stuck in the power failure, and the use effect is good.

The embodiment of the fourth aspect of the present application proposes a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the motor control method as in any of the above-mentioned embodiments is implemented.

The computer-readable storage medium provided in the present application implements the steps of the motor control method in any of the above embodiments when the computer program is executed by the processor. Therefore, the computer-readable storage medium includes all of the motor control methods in any of the above embodiments. Beneficial effect.

In the description of this specification, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance, unless expressly stipulated and limited otherwise; the terms "connected" and " "Installation" and "fixation" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in this application can be understood according to specific circumstances.

In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in this application In at least one embodiment or example. In this specification, the schematic representations of the above-mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

The above descriptions are only preferred embodiments of the application, and are not intended to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

A motor control method, which includes:

Obtaining the bus voltage of the motor;

It is determined that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and the switch tube of the intelligent power module of the motor is controlled according to the bus voltage and the voltage command value to stop the motor, The first voltage threshold is greater than the second voltage threshold.
The motor control method according to claim 1, wherein it is determined that the bus voltage is greater than a first voltage threshold or the bus voltage is less than a second voltage threshold, and the intelligent control of the motor is controlled according to the bus voltage and the voltage command value. The steps of the switch tube of the power module include:

Determining that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and selecting the voltage command value;

The upper-arm switch tube of the intelligent power module is controlled to be turned off, and the lower-arm switch tube of the intelligent power module is controlled according to the difference between the voltage command value and the bus voltage.
3. The motor control method according to claim 2, wherein the step of controlling the switch tube of the lower arm of the smart power module according to the difference between the voltage command value and the bus voltage includes:

If the difference is greater than 0, the duty cycle of the control signal is reduced according to the increase in the absolute value of the difference, or the difference is less than 0, and the control signal is made according to the increase in the absolute value of the difference. The duty cycle increases;

The lower-side switch tube of the smart power module is controlled according to the duty cycle of the control signal, wherein the control signal is high-level and the lower-side switch tube of the smart power module is turned on, and the control signal is low The switch tube of the lower arm of the smart power module is turned off.
The motor control method according to claim 2 or 3, wherein the step of selecting the voltage command value specifically includes:

The bus voltage is greater than the first voltage threshold, and the first voltage threshold is used as the voltage command value;

If the bus voltage is less than the second voltage threshold, a third voltage threshold is used as the voltage command value, and the third voltage threshold is a rectified AC grid voltage.
The motor control method according to claim 2 or 3, wherein the step of selecting the voltage command value specifically includes:

Any value within a preset value range is selected as the voltage command value, wherein the preset value range is greater than or equal to the minimum value of the system operating voltage and less than or equal to the first voltage threshold.
A motor control device, which includes:

A voltage sampler for obtaining the bus voltage of the motor;

A memory, the memory is used to store a computer program;

A processor, which implements when the processor executes the computer program:

It is determined that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and the switch tube of the intelligent power module of the motor is controlled according to the bus voltage and the voltage command value to stop the motor, The first voltage threshold is greater than the second voltage threshold.
The motor control device according to claim 6, wherein the processor executes the determination that the bus voltage is greater than a first voltage threshold or the bus voltage is less than a second voltage threshold, and controls the bus voltage according to the bus voltage and the voltage command value The steps of the switch tube of the intelligent power module of the motor specifically include:

Determining that the bus voltage is greater than the first voltage threshold or the bus voltage is less than the second voltage threshold, and selecting the voltage command value;

The upper-arm switch tube of the intelligent power module is controlled to be turned off, and the lower-arm switch tube of the intelligent power module is controlled according to the difference between the voltage command value and the bus voltage.
8. The motor control device according to claim 7, wherein the processor executes the step of controlling the lower arm switch tube of the smart power module according to the difference between the voltage command value and the bus voltage, which specifically includes :

If the difference is greater than 0, the duty cycle of the control signal is reduced according to the increase in the absolute value of the difference, or the difference is less than 0, and the control signal is made according to the increase in the absolute value of the difference. The duty cycle increases;

The lower-side switch tube of the smart power module is controlled according to the duty cycle of the control signal, wherein the control signal is high-level and the lower-side switch tube of the smart power module is turned on, and the control signal is low The switch tube of the lower arm of the smart power module is turned off.
The motor control device according to claim 7 or 8, wherein the step of selecting the voltage command value executed by the processor specifically includes:

The bus voltage is greater than the first voltage threshold, and the first voltage threshold is used as the voltage command value;

If the bus voltage is less than the second voltage threshold, a third voltage threshold is used as the voltage command value, and the third voltage threshold is a rectified AC grid voltage.
The motor control device according to claim 7 or 8, wherein the step of selecting the voltage command value executed by the processor specifically includes:

Any value within a preset value range is selected as the voltage command value, wherein the preset value range is greater than or equal to the minimum value of the system operating voltage and less than or equal to the first voltage threshold.
A motor system, which includes:

Motor

The motor control device according to any one of claims 6 to 10.
A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the motor control method according to any one of claims 1 to 5 is realized.