WO2019227873A1

WO2019227873A1 - Power failure protection control method and device, and permanent magnet synchronous motor control system

Info

Publication number: WO2019227873A1
Application number: PCT/CN2018/116878
Authority: WO
Inventors: 程云峰; 齐利民
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: 2018-05-29
Filing date: 2018-11-22
Publication date: 2019-12-05
Also published as: CN108649550B; CN108649550A

Abstract

The present invention provides a power failure protection control method for a permanent magnet synchronous motor control system, a power failure protection control device, and a permanent magnet synchronous motor control system. The power failure protection control method comprises: measuring a voltage value of a direct current bus module in real time; determining whether the duration, for which the voltage value reduces from a first preset voltage value to a second preset voltage value, is less than or equal to a first preset duration; and when the duration is less than or equal to the first preset duration, setting all switch tubes of an intelligent power module into a high-resistance state. All switch tubes of the intelligent power module are set to the high-resistance state, such that the voltage generated, at the direct current bus module, by the back electromotive force transiently produced by a permanent magnet synchronous motor is less than a safety voltage, avoiding the component damage caused by relatively high voltage generated, at the direct current bus module, by the back electromotive force produced by the permanent magnet synchronous motor due to power failure.

Description

Method and device for controlling power-down protection and permanent magnet synchronous motor control system

This application claims the priority of a Chinese patent application filed on May 29, 2018 with the Chinese Patent Office, application number 201810527882.5, and the invention name "Method, Device and Control for Permanent Magnet Synchronization Control", all of which are all The contents are incorporated herein by reference.

Technical field

The invention relates to the field of motor control, in particular to a method for power-down protection control of a permanent magnet synchronous motor control system, a device for power-down protection control, and a control system for a permanent magnet synchronous motor.

Background technique

When the permanent magnet synchronous motor runs at a high speed and enters a weak magnetic state, if there is a power outage on the AC power side, the permanent magnet synchronous motor will generate a large back-EMF and pass the Intelligent Power Module (IPM) to control the permanent magnet. The core component of the magnetic synchronous motor is to directly charge the DC bus module used for power supply, and the DC bus module may be damaged due to overvoltage.

Summary of the Invention

The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

For this reason, a first aspect of the present invention is to provide a method for controlling power-down protection.

A second aspect of the present invention is to provide a device for power failure protection control.

A third aspect of the present invention is to provide a control system for a permanent magnet synchronous motor.

In view of this, according to a first aspect of the present invention, a method for power-off protection control is provided for a permanent magnet synchronous motor control system, wherein the permanent magnet synchronous motor control system includes a DC bus module, an intelligent power module, and a DC bus module. The method for providing DC power to the intelligent power module and controlling the power failure protection includes: real-time counting the voltage value of the DC bus module; judging whether the time period during which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset voltage value; Set the duration; when the duration is less than or equal to the first preset duration, set all the switches of the intelligent power module to a high resistance state.

The power-down protection control method provided by the present invention counts the voltage value of the DC bus module in real time, and determines whether a power failure occurs by monitoring the voltage value of the DC bus module. Specifically, the voltage value of the DC bus module is determined by the first Whether the time period during which the preset voltage value is reduced to the second preset voltage value is less than or equal to the first preset time period, that is, the voltage value of the DC bus module is reduced from the first preset voltage value to the second preset voltage within a short time. Value, it is considered that a power failure situation occurs, and all the switches of the intelligent power module are set to a high resistance state, so that the voltage generated on the DC bus module by the back-EMF momentarily generated by the permanent magnet synchronous motor is lower than the safe voltage, avoiding The power-down caused the back-EMF generated by the permanent magnet synchronous motor to form a higher voltage on the DC bus module, causing component damage.

In addition, the method for controlling power-down protection in the above technical solution provided by the present invention may also have the following additional technical features:

In the above technical solution, preferably, after setting all the switches of the intelligent power module to a high-resistance state, the method further includes: judging whether a duration of a voltage value greater than a third preset voltage is greater than a second preset duration; When the duration is longer than the second preset duration, the switch tube corresponding to the lower arm of the intelligent power module is turned on and the switch tube corresponding to the upper arm of the intelligent power module is turned off until the permanent magnet synchronous motor is stopped; otherwise, the intelligent All switches of the power module are set to high resistance.

In this technical solution, after setting all the switching tubes of the intelligent power module to a high resistance state, the voltage value of the DC bus will increase under the action of the back-EMF of the permanent magnet synchronous motor. In order to avoid the voltage of the DC bus module If the value is too high, an overvoltage condition occurs in the DC bus module. It is determined whether the duration of the voltage value is greater than the third preset voltage is greater than the second preset duration. Only when the duration is greater than the second preset duration, controls the power of the intelligent power module. The switch tube corresponding to the bridge arm is turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module is turned off, thereby separating the DC bus module from the permanent magnet synchronous motor circuit until the permanent magnet synchronous motor stops, thereby avoiding the voltage rise of the DC bus High causes DC bus module to be damaged due to high voltage.

In any of the above technical solutions, preferably, the voltage value is obtained from a known resistance measurement in parallel on the DC bus module.

In this technical solution, the voltage value of the DC bus module can be determined by connecting a known resistance in parallel with the DC bus. Specifically, directly measure the voltage of the resistor to directly obtain the voltage of the DC bus module, so as to determine the intelligent power according to the measurement result. The state of all the switching tubes of the module guarantees the voltage safety of the DC bus module, and avoids the excessive voltage of the DC bus module causing damage to the device.

In any of the above technical solutions, preferably, the intelligent power module is a three-phase bridge circuit composed of six switching tubes.

In this technical solution, the intelligent power module provides power for the permanent magnet synchronous motor, and internally integrates fault detection circuits such as overvoltage, overcurrent, and overheating. When it is determined that a power failure occurs, the internal six switch tubes are set. It is a high-resistance state, reducing the voltage generated on the DC bus by the back-EMF generated by the permanent magnet synchronous motor in the event of power failure, so as to avoid damage to the components. Further, after the switch tube is set to a high-resistance state To detect whether the duration of the voltage on the DC bus module exceeding the third preset voltage is greater than the second preset duration, and when the duration of the voltage on the DC bus module is greater than the second preset duration, the switch of the switch tube corresponding to the lower arm of the intelligent power module is turned on and intelligent The switch tube corresponding to the upper bridge arm of the power module is turned off, thereby reducing the voltage on the DC bus module and avoiding excessive overvoltage time of the DC bus module, resulting in damage to components.

In any of the above technical solutions, preferably, the switching tube is an insulated gate bipolar transistor.

In this technical solution, insulated gate bipolar transistors (IGBTs) have the characteristics of low driving power and low saturation voltage. Therefore, intelligent power modules using insulated gate bipolar transistors effectively degrade the control system. Power consumption reduces heat generation.

In any of the above technical solutions, preferably, the first preset duration is less than or equal to 2 ms, and the second preset duration is less than or equal to 20 ms.

In this technical solution, the first preset duration is less than or equal to 2ms, and preferably, the first preset duration is less than or equal to 1ms, so as to ensure that the power failure situation is accurately determined according to the first preset duration, and the second preset duration is preferably It is 10ms to avoid the damage caused by the excessively long time caused by the DC bus module.

In any of the above technical solutions, preferably, the second preset voltage value is 1/3 times or more and 2/3 times or less the first preset voltage value; the third preset voltage value is 1.2 times or more and 1.8 times or less. Times the first preset voltage value.

In this technical solution, the second preset voltage value is greater than or equal to 1/3 times the first preset voltage value and less than or equal to 2/3 times the first preset voltage value, and the first preset voltage value and the second preset voltage are The larger the difference between the voltage values is, the larger the voltage drop on the DC bus module is reflected, that is, the higher the possibility of power failure, preferably, the second preset voltage value is the first preset voltage value. Half; the third preset voltage value is set to 1.2 to 1.8 times the first preset voltage value, thereby improving the accuracy of determining overvoltage. When the first preset voltage value is the rated voltage value of the DC bus module, preferably, the third preset voltage value is equal to 1.5 times the first preset voltage value, so as to avoid directly causing the DC bus because the third preset voltage value is too high. Module is damaged.

According to a second aspect of the present invention, a device for power-off protection control is provided. A control system for a permanent magnet synchronous motor includes a DC bus module and an intelligent power module. The DC bus module provides DC power to the intelligent power module. The device for electrical protection control includes: a statistics unit for real-time statistics of the voltage value of the DC bus module; a judgment unit for judging whether the time period during which the voltage value decreases from the first preset voltage value to the second preset voltage value is less than or equal to the first A preset duration; a control unit configured to set all the switches of the intelligent power module to a high-resistance state when the duration is less than or equal to the first preset duration.

In the power-off protection control device provided by the present invention, the statistics unit counts the voltage value of the DC bus module in real time, and determines whether a power failure occurs by monitoring the voltage value of the DC bus module. Specifically, the judgment unit determines the voltage on the DC bus module. Whether the time period during which the value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset duration, that is, the voltage value of the DC bus module is reduced by the first preset voltage value in a short period of time. The second preset voltage value is considered to be a power failure. The control unit sets all the switches of the intelligent power module to a high resistance state, so that the voltage generated on the DC bus module by the back-EMF generated by the permanent magnet synchronous motor is low. The safety voltage prevents the back electromotive force generated by the permanent magnet synchronous motor from forming a higher voltage on the DC bus module due to power failure, which causes component damage.

In addition, the device for power-off protection control in the above technical solution provided by the present invention may also have the following additional technical features:

In the above technical solution, preferably, the judging unit is further configured to judge whether the duration of the voltage value greater than the third preset voltage is greater than the second preset duration; the control unit is further configured to, when the duration is greater than the second preset duration, Control the switch tube corresponding to the lower bridge arm of the intelligent power module to be turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module to be turned off until the permanent magnet synchronous motor is stopped; and when the duration is less than or equal to the second preset duration, All switches of the intelligent power module are set to a high resistance state.

In this technical solution, after setting all the switching tubes of the intelligent power module to a high resistance state, the voltage value of the DC bus will increase under the action of the back-EMF of the permanent magnet synchronous motor. In order to avoid the voltage of the DC bus module If the value is too high, an overvoltage condition occurs in the DC bus module. The judging unit judges whether the duration of the voltage value greater than the third preset voltage is greater than the second preset duration. Only when the duration is greater than the second preset duration, the control unit controls the intelligence. The switch tube corresponding to the lower bridge arm of the power module is turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module is turned off, thereby separating the DC bus module from the permanent magnet synchronous motor circuit until the permanent magnet synchronous motor stops, thereby avoiding DC The increased voltage on the bus leads to damage to the DC bus module due to the high voltage.

In the above technical solution, preferably, the voltage value is obtained by measuring a known resistance in parallel on the DC bus module.

According to a third aspect of the present invention, a permanent magnet synchronous motor control system is provided. The permanent magnet synchronous motor control system includes an AC power module, a rectifier module, a DC bus module, an intelligent power module, a permanent magnet synchronous motor, and a microcomputer. Control module; AC power module is used to provide AC power for rectifier module; rectifier module rectifies AC power and outputs DC power to DC bus module; intelligent power module controls permanent magnet synchronous motor operation according to control instructions sent by micro control module; micro control module executes A method for controlling power-down protection according to any one of the above.

In this technical solution, the micro control module executes any one of the power-down protection control methods described above, and has all the beneficial technical effects of the power-down protection control method described above. Therefore, the permanent magnet synchronous motor control system including the micro-control module is also the same. It has all the beneficial technical effects of the above-mentioned power-down protection control method, and is not repeated here.

Additional aspects and advantages of the invention will become apparent in the following description or will be learned through practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

FIG. 1 shows a schematic flowchart of a power-down protection control method according to a first embodiment of the present invention;

FIG. 2 is a schematic flowchart of a method for controlling power-down protection according to another embodiment of the present invention; FIG.

FIG. 3 shows a schematic block diagram of a device for power-off protection control according to a first embodiment of the present invention; FIG.

4 shows a schematic block diagram of a device for power-off protection control according to another embodiment of the present invention;

5 shows a schematic block diagram of a permanent magnet synchronous motor control system according to an embodiment of the present invention;

FIG. 6 shows a schematic block diagram of a connection relationship of a permanent magnet synchronous motor control system according to an embodiment of the present invention.

Reference signs:

The corresponding relationship between the reference numerals and the names of the components in FIG. 6 is:

602 AC power module, 604 rectifier module, 606 DC bus module, 608 intelligent power module, 610 permanent magnet synchronous motor, 612 micro-control module.

Detailed ways

In order to understand the above-mentioned objects, features, and advantages of the present invention more clearly, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other.

In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways than those described herein. Therefore, the protection scope of the present invention is not limited to the specifics disclosed below. Limitations of Examples.

An embodiment of the first aspect of the present invention provides a method for controlling power failure protection for a permanent magnet synchronous motor control system. The permanent magnet synchronous motor control system includes a DC bus module and an intelligent power module. The DC bus module is intelligent. The power module provides DC power.

FIG. 1 shows a schematic flowchart of a power-down protection control method according to a first embodiment of the present invention.

As shown in FIG. 1, the method for controlling power-down protection according to the first embodiment of the present invention includes:

S102: Calculate the voltage value of the DC bus module in real time;

S104. Determine whether the time period during which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset time period;

S106. When the duration is less than or equal to the first preset duration, all switches of the intelligent power module are set to a high resistance state.

In this embodiment, the voltage value of the DC bus module is counted in real time, and the power failure situation is determined by monitoring the voltage value of the DC bus module. Specifically, the voltage value of the DC bus module is determined by the first preset voltage value. Whether the duration of reducing to the second preset voltage value is less than or equal to the first preset duration, that is, the voltage value of the DC bus module is reduced from the first preset voltage value to the second preset voltage value within a short period of time, which is considered to occur In the case of power failure, all switches of the intelligent power module are set to a high-resistance state, so that the voltage generated on the DC bus module by the back-EMF generated by the permanent magnet synchronous motor instantaneously is lower than the safe voltage. The back-EMF generated by the magnetic synchronous motor forms a higher voltage in the DC bus module, causing component damage.

FIG. 2 is a schematic flowchart of a power-down protection control method according to another embodiment of the present invention.

As shown in FIG. 2, the method for controlling power-down protection according to the first embodiment of the present invention includes:

S202: Calculate the voltage value of the DC bus module in real time;

S204. Determine whether the time period during which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset time period;

S206. When the duration is less than or equal to the first preset duration, all switches of the intelligent power module are set to a high resistance state;

S208: Determine whether the duration of the voltage value greater than the third preset voltage is greater than the second preset duration;

S210: When the duration is longer than the second preset duration, control the switch tube corresponding to the lower bridge arm of the intelligent power module to be turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module to be turned off until the permanent magnet synchronous motor is stopped, otherwise Set all the switches of the intelligent power module to a high resistance state.

In this embodiment, after setting all the switching tubes of the intelligent power module to a high resistance state, the voltage value of the DC bus will increase under the action of the back-EMF of the permanent magnet synchronous motor. In order to avoid the voltage of the DC bus module If the value is too high, an overvoltage condition occurs in the DC bus module. It is determined whether the duration of the voltage value is greater than the third preset voltage is greater than the second preset duration. Only when the duration is greater than the second preset duration, controls the power of the intelligent power module. The switch tube corresponding to the bridge arm is turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module is turned off, thereby separating the DC bus module from the permanent magnet synchronous motor circuit until the permanent magnet synchronous motor stops, thereby avoiding the voltage rise of the DC bus High causes DC bus module to be damaged due to high voltage.

In one embodiment of the present invention, the voltage value is obtained from a known resistance measurement in parallel on the DC bus module.

In this embodiment, the voltage value of the DC bus module can be determined by connecting a known resistance in parallel with the DC bus. Specifically, directly measuring the voltage of the resistance directly obtains the voltage of the DC bus module, thereby determining the intelligent power according to the measurement result. The state of all the switching tubes of the module guarantees the voltage safety of the DC bus module, and avoids the excessive voltage of the DC bus module causing damage to the device.

In one embodiment of the present invention, the intelligent power module is a three-phase bridge circuit composed of six switching tubes.

In this embodiment, the intelligent power module provides power for the permanent magnet synchronous motor, and internally integrates fault detection circuits such as overvoltage, overcurrent, and overheating. When determining that a power failure occurs, the internal six switch tubes are set. It is a high-resistance state, reducing the voltage generated on the DC bus by the back-EMF generated by the permanent magnet synchronous motor in the event of power failure, so as to avoid damage to the components. Further, after the switch tube is set to a high-resistance state To detect whether the duration of the voltage on the DC bus module exceeding the third preset voltage is greater than the second preset duration, and when the duration of the voltage on the DC bus module is greater than the second preset duration, the switch of the switch tube corresponding to the lower arm of the intelligent power module is controlled The switch tube corresponding to the upper bridge arm of the power module is turned off, thereby reducing the voltage on the DC bus module and avoiding excessive overvoltage time of the DC bus module, resulting in damage to components.

In one embodiment of the present invention, the switching transistor is an insulated gate bipolar transistor.

In this embodiment, an insulated gate bipolar transistor (IGBT) has the characteristics of low driving power and low saturation voltage. Therefore, an intelligent power module using an insulated gate bipolar transistor effectively degrades the control system. Power consumption reduces heat generation.

In an embodiment of the present invention, the first preset duration is less than or equal to 2 ms, and the second preset duration is less than or equal to 20 ms.

In this embodiment, the first preset duration is less than or equal to 2ms, preferably, the first preset duration is less than or equal to 1ms, so as to ensure that the power failure situation is accurately determined according to the first preset duration, and the second preset duration is preferably It is 10ms to avoid the damage caused by the excessively long time caused by the DC bus module.

In an embodiment of the present invention, the second preset voltage value is 1/3 times or more and 2/3 times or less the first preset voltage value; the third preset voltage value is 1.2 times or more and 1.8 times or less. A preset voltage value.

In this embodiment, the second preset voltage value is greater than or equal to 1/3 times the first preset voltage value and less than or equal to 2/3 times the first preset voltage value, and the first preset voltage value and the second preset voltage are The larger the difference between the voltage values is, the larger the voltage drop on the DC bus module is reflected, that is, the higher the possibility of power failure, preferably, the second preset voltage value is the first preset voltage value. Half; the third preset voltage value is set to 1.2 to 1.8 times the first preset voltage value, thereby improving the accuracy of determining overvoltage. When the first preset voltage value is the rated voltage value of the DC bus module, preferably, the third preset voltage value is equal to 1.5 times the first preset voltage value, so as to avoid directly causing the DC bus because the third preset voltage value is too high. Module is damaged.

An embodiment of the second aspect of the present invention provides a device for power-off protection control. A control system for a permanent magnet synchronous motor includes a DC bus module and an intelligent power module. The DC bus module provides DC power to the intelligent power module.

FIG. 3 shows a schematic block diagram of a device 300 for power-off protection control according to a first embodiment of the present invention.

As shown in FIG. 3, the power-off protection control device 300 according to the first embodiment of the present invention includes: a statistics unit 302 for real-time statistics of the voltage value of the DC bus module; a judgment unit 304 for judging the voltage value from the first Whether the duration when the preset voltage value is reduced to the second preset voltage value is less than or equal to the first preset duration; the control unit 306 is configured to set all the switches of the intelligent power module when the duration is less than or equal to the first preset duration; It is a high resistance state.

In the power-off protection control device provided by the present invention, the statistics unit 302 counts the voltage value of the DC bus module in real time, and determines whether a power failure occurs by monitoring the voltage value of the DC bus module. Specifically, the judgment unit 304 determines Whether the time period for which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset time period, that is, the voltage value of the DC bus module is reduced from the first preset voltage value in a short period of time The second preset voltage value is considered to be a power failure. The control unit 306 sets all the switches of the intelligent power module to a high resistance state, so that the back-EMF generated by the permanent magnet synchronous motor is generated on the DC bus module. The voltage is lower than the safe voltage, to avoid the back electromotive force generated by the permanent magnet synchronous motor due to power failure to form a higher voltage on the DC bus module, causing component damage.

FIG. 4 shows a schematic block diagram of a device 400 for power-off protection control according to another embodiment of the present invention.

As shown in FIG. 4, the apparatus 400 for controlling power failure protection according to the first embodiment of the present invention includes: a statistics unit 402 for real-time statistics of the voltage value of the DC bus module; and a judgment unit 404 for judging the voltage value from the first Whether the duration when the preset voltage value is reduced to the second preset voltage value is less than or equal to the first preset duration; the control unit 406 is configured to set all the switches of the intelligent power module when the duration is less than or equal to the first preset duration; Is a high-resistance state; the judging unit 404 is further configured to judge whether the duration of the voltage value is greater than the third preset voltage is greater than the second preset duration; the control unit 406 is further configured to control when the duration is greater than the second preset duration The switch tube corresponding to the lower bridge arm of the intelligent power module is turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module is turned off until the permanent magnet synchronous motor is stopped; and when the duration is less than or equal to the second preset time, the intelligent All switches of the power module are set to high resistance.

In this embodiment, after setting all the switching tubes of the intelligent power module to a high resistance state, the voltage value of the DC bus will increase under the action of the back-EMF of the permanent magnet synchronous motor. In order to avoid the voltage of the DC bus module If the value is too high, an overvoltage condition occurs in the DC bus module. The judging unit 404 judges whether the duration of the voltage value greater than the third preset voltage is greater than the second preset duration. Only when the duration is greater than the second preset duration, the control unit 406 Controlling the switch tube corresponding to the lower bridge arm of the intelligent power module is turned on and the switch tube corresponding to the upper bridge arm of the intelligent power module is turned off, thereby separating the DC bus module from the permanent magnet synchronous motor circuit until the permanent magnet synchronous motor stops, and Avoid increasing the voltage of the DC bus to cause damage to the DC bus module due to excessive voltage.

In this embodiment, the intelligent power module provides power for the permanent magnet synchronous motor, and internally integrates fault detection circuits such as overvoltage, overcurrent, and overheating. When determining that a power failure occurs, the internal six switch tubes are set. It is a high-resistance state, reducing the voltage generated on the DC bus by the back-EMF generated by the permanent magnet synchronous motor in the event of power failure, so as to avoid damage to the components. Further, after the switch tube is set to a high-resistance state To detect whether the duration of the voltage on the DC bus module exceeding the third preset voltage is greater than the second preset duration, and when the duration of the voltage on the DC bus module is greater than the second preset duration, the switch of the switch tube corresponding to the lower arm of the intelligent power module is turned on and intelligent The switch tube corresponding to the upper bridge arm of the power module is turned off, thereby reducing the voltage on the DC bus module and avoiding excessive overvoltage time of the DC bus module, resulting in damage to components.

An embodiment of the third aspect of the present invention provides a permanent magnet synchronous motor control system. FIG. 5 shows a schematic block diagram of a permanent magnet synchronous motor control system 500 according to an embodiment of the present invention.

As shown in FIG. 5, the permanent magnet synchronous motor control system 500 includes: an AC power module 502, a rectifier module 504, a DC bus module 506, an intelligent power module 508, a permanent magnet synchronous motor 510, and a micro-control module 512; The rectifier module 504 provides AC power; the rectifier module 504 rectifies the AC power and outputs DC power to the DC bus module 506; the intelligent power module 508 controls the operation of the permanent magnet synchronous motor 510 according to the control instruction sent by the micro control module 512; the micro control module 512 executes A method for controlling power-down protection according to any one of the above.

In this embodiment, the micro-control module 512 executes any of the above-mentioned methods of power-down protection control, and has all the beneficial technical effects of the method of the above-mentioned power-down protection control. Therefore, the permanent magnet synchronous motor control system including the micro-control module 512 500, which also has all the beneficial technical effects of the foregoing power-down protection control method, which will not be repeated here.

The technical scheme of the present invention has been described in detail above with reference to the accompanying drawings. The present invention provides a method for power failure protection control. When a permanent magnet synchronous motor is running at high speed and enters a weak magnetic state, if there is a power failure on the AC power side, During any processing, the DC bus module and the micro control module will lose power. At this time, the permanent magnet synchronous motor will generate a back electromotive force after power failure, and the generated back electromotive force will be directly loaded on the DC bus module to charge the DC bus module. As a result, the voltage of the DC bus module rises instantly, and an overvoltage condition occurs.

FIG. 6 shows a schematic block diagram of a connection relationship of a permanent magnet synchronous motor control system according to an embodiment of the present invention. In this application, the voltage on the DC bus module 606 is monitored by the power-down protection module in the micro-control module 612. When a power failure is determined, the switch in the intelligent power module 608 is set to a high resistance state, so that the The voltage on the bus module is reduced to avoid the above situation. Since the permanent magnet synchronous motor 610 does not stop rotating instantly, it will continue to rotate for a period of time, and the back electromotive force will continue to act on the DC bus module 606. By judging that the voltage value is greater than the first Whether the duration of the three preset voltages is greater than the second preset duration to determine whether to adjust the state of the switching tube in the intelligent power module 608, thereby ensuring the safety of the DC bus module 606. The rectifier module 604 includes at least a secondary tube for rectifying the AC power module 602, and capacitors are connected in parallel at both ends of the DC bus module 606.

The above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

A power-down protection control method for a permanent magnet synchronous motor control system, characterized in that the permanent magnet synchronous motor control system includes a DC bus module and an intelligent power module, and the DC bus module is the intelligent power module Providing direct current, the method for controlling power-down protection includes:

Statistics the voltage value of the DC bus module in real time;

Determining whether the time period during which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset time period;

When the duration is less than or equal to the first preset duration, all switches of the intelligent power module are set to a high-resistance state.
The method for controlling power-down protection according to claim 1, wherein:

After setting all the switches of the intelligent power module to a high resistance state, it also includes:

Determining whether the duration of the voltage value greater than the third preset voltage is greater than the second preset duration;

When the duration is longer than the second preset duration, controlling a switch tube corresponding to a lower bridge arm of the intelligent power module to be turned on and a switch tube corresponding to an upper bridge arm of the intelligent power module to be turned off until The magnetic synchronous motor is stopped; otherwise, all the switching tubes of the intelligent power module are set to a high resistance state.
The method for controlling power-down protection according to claim 2, wherein:

The voltage value is obtained by measuring a known resistance in parallel on the DC bus module.
The method for controlling power-down protection according to claim 3, wherein:

The intelligent power module is a three-phase bridge circuit composed of six switching tubes.
The method for controlling power-down protection according to claim 4, wherein:

The switching tube is an insulated gate bipolar transistor.
The method for controlling power-down protection according to claim 3, wherein the first preset duration is less than or equal to 2ms, and the second preset duration is less than or equal to 20ms.
The method for controlling power-down protection according to claim 3, wherein:

The second preset voltage value is greater than or equal to 1/3 times and less than or equal to 2/3 times the first preset voltage value; the third preset voltage value is greater than or equal to 1.2 times and less than or equal to 1.8 times the first preset voltage value. Preset voltage value.
A power failure protection control device for a permanent magnet synchronous motor control system, characterized in that the permanent magnet synchronous motor control system includes a DC bus module and an intelligent power module, and the DC bus module is the intelligent power module Providing direct current, the device for controlling power failure protection includes:

A statistics unit, configured to count the voltage value of the DC bus module in real time;

A judging unit, configured to judge whether the time period during which the voltage value is reduced from the first preset voltage value to the second preset voltage value is less than or equal to the first preset time period;

The control unit is configured to set all the switches of the intelligent power module to a high-resistance state when the duration is less than or equal to the first preset duration.
The device for controlling power-down protection according to claim 8, wherein:

The determining unit is further configured to determine whether a duration of the voltage value greater than a third preset voltage is greater than a second preset duration;

The control unit is further configured to control, when the duration is greater than the second preset duration, a switch tube corresponding to a lower bridge arm of the intelligent power module to be turned on and a corresponding one of the upper bridge arm of the intelligent power module. The switching tubes are turned off until the permanent magnet synchronous motor is stopped; and when the duration is less than or equal to the second preset duration, all the switching tubes of the intelligent power module are set to a high-resistance state.
A control system for a permanent magnet synchronous motor, comprising:

The permanent magnet synchronous motor control system includes an AC power module, a rectifier module, a DC bus module, an intelligent power module, a permanent magnet synchronous motor, and a micro-control module;

The AC power module is configured to provide AC power to the rectifier module;

The rectifying module rectifies the AC power and outputs DC power to a DC bus module;

The intelligent power module controls the operation of the permanent magnet synchronous motor according to a control instruction sent by the micro control module;

The micro-control module executes the power-down protection control method according to any one of claims 1 to 7.