Motor driving method, system and device for improving noise and readable storage medium

Abstract

The invention discloses a motor driving method, system and device for improving noise and a readable storage medium. The method comprises the steps that an inverter is controlled through a field-oriented control unit; the motor frequency is collected in real time according to a set period, and whether the difference between the motor frequency of the current period and the motor frequency of the previous period or the difference between the motor frequency of the current period and the motor set frequency exceeds a set difference threshold value or not is judged; if yes, adaptively increasing the frequency of part of modules in the field-oriented control unit in real time under the constraint condition of the set frequency in combination with the idle time of the chip and the execution time of each module; and a forward difference method error solving module is added in the magnetic field orientation control unit, and the module is used for correcting the position at the next moment after the frequency is increased and the angle output by the speed observer module. According to the invention, the fixed frequency is changed into the frequency for adjusting the motor control link, so that the noise is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of noise regulation, and more specifically, relates to a motor drive method, system, device, and readable storage medium for improving noise. Background Art

[0002] At present, permanent magnet synchronous motors have the characteristics of simple structure, fast speed regulation, and low cost, and are widely used in the household appliance field. However, the noise of permanent magnet synchronous motors is also a common problem. Its noise includes mechanical noise generated by bearing friction and electromagnetic noise generated by non-sinusoidal magnetic field waveforms. The electromagnetic noise is particularly uncomfortable for the human ear. To improve the user experience, it is necessary to design an inverter for motor control and its control method to reduce motor noise.

[0003] The patent with the patent number CN107241048A discloses a method for reducing motor noise and vibration. The solution is to obtain the harmonic components of the motor induced voltage, set the harmonic component coefficient of the motor induced voltage, calculate the current harmonic coefficient, and superimpose the harmonic components and output them to the motor. This solution involves a large number of trigonometric function operations, which undoubtedly places high demands on the computing power of the chip and is not advisable for fields with strict cost requirements. Summary of the Invention

[0004] To solve the deficiencies in the prior art, the present invention provides a motor drive method, system, device, and readable storage medium for improving noise.

[0005] The present invention adopts the following technical solutions.

[0006] The first aspect of the present invention proposes a motor drive method for improving noise, which is characterized by including: Controlling the inverter through a field-oriented control unit; Real-time collecting the motor frequency at a set period, and judging whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds a set difference threshold; If so, combining the chip idle time and the execution time of each module, under the constraint condition of the set frequency, adaptively and real-time increasing the frequency of some modules in the field-oriented control unit; and adding a forward difference method to solve the error module in the field-oriented control unit, using this module to correct the angle output by the position and speed observer module in the field-oriented control unit at the next moment after the frequency increase, and inputting the corrected angle into the inverse Park module in the field-oriented control unit.

[0007] Preferably, the difference threshold is set in the range of .

[0008] Preferably, the constraint condition of the set frequency is specifically as follows: Before the frequency is increased, the frequencies of some modules in the field-oriented control unit and all other modules except some modules are respectively , ; , equal and not an even multiple of the fundamental frequency of the motor; Obtain the execution time of each module of the field-oriented control unit before the frequency is increased , and the constraint condition of the frequency of some modules after the frequency is increased is:

[0009] In the formula: is the fundamental frequency of the motor.

[0010] Preferably, the field-oriented control unit includes three PI modules, a park module, a clarke module, an inverse Park module, an inverse clarke module, and a position and speed observer module. The partial modules include the inverse Park and inverse clarke modules, and the added forward difference method solution error module always maintains the same frequency as these partial modules.

[0011] Preferably, the real-time adaptive increase in the frequency of some modules in the field-oriented control unit is specifically as follows: Obtain the current chip idle time and the execution time of some modules in the field-oriented control unit ; Calculate the time for some modules to increase the frequency at this time:

[0012] In the formula: is the frequency of some modules before the frequency is increased, is the frequency of some modules after the frequency is increased; If , then stop increasing the frequency of some modules; if , then increase the frequency of some modules until is reached; if , then decrease the frequency of some modules until is reached, where is the reserved time for other programs to run normally as set; repeat the above content at the set period.

[0013] Preferably, the obtaining of the current chip idle time is specifically as follows: ​​​Count once every 1us in the main loop. Record the total count icnt at the start of the algorithm interruption executed by the chip, and clear the count icnt at the end of the algorithm interruption execution. Then the idle time of the chip is icnt multiplied by 1us.

[0014] Preferably, add a forward difference method to solve the error module in the field-oriented control unit, and use this module to correct the angle output by the position and speed observer module at the next moment after the frequency is increased. Specifically: Calculate the derivative of the angle output by the position and speed observer module using the forward difference method :

[0015] In the formula: and are the angles output by the position and speed observer module at the next moment and the current moment respectively; is the frequency of the previous part of the module before the frequency is increased; The angle output by the position and speed observer module at the next moment after correction is:

[0016] In the formula: is the frequency of the latter part of the module after the frequency is increased.

[0017] The second aspect of the present invention proposes a motor drive system for improving noise using the method described in the first aspect of the present invention, including a field-oriented control unit module, a difference judgment module, a frequency adaptive adjustment module, and a forward difference correction module, characterized in that: Field-oriented control unit module: used to control the inverter through the field-oriented control unit; Difference judgment module: used to collect the motor frequency in real time at a set period, and judge whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds the set difference threshold; Frequency adaptive adjustment module; used to, if so, combine the chip idle time and the execution time of each module, and adaptively increase the frequency of some modules in the field-oriented control unit in real time under the constraint conditions of the set frequency; Forward difference correction module: used to add a forward difference method to solve the error module in the field-oriented control unit, use this module to correct the angle output by the position and speed observer module in the field-oriented control unit at the next moment after the frequency is increased, and input the corrected angle into the inverse Park module in the field-oriented control unit.

[0018] A third aspect of the present invention provides a device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the steps of a motor driving method for improving noise according to the first aspect of the present invention.

[0019] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, uses the steps of a motor driving method for improving noise according to any one of the first aspect of the present invention.

[0020] The beneficial effects of the present invention are as follows. Compared with the prior art, the present invention changes from a fixed frequency to adjusting the frequency of the motor control link, and corrects the angle by the forward difference method, thereby reducing noise, improving the high-frequency electromagnetic noise of the motor from the perspective of the inverter, enhancing the user experience, and saving costs. The present invention combines automatic identification of the idle time condition frequency of the current chip and adjusts the frequencies of different modules in the control link differently, reducing the computing amount of the chip. The present invention mode judges whether to adjust the frequency according to the magnitude and fluctuation of the motor frequency, promoting the motor to reach dynamic stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a three-phase inverter circuit diagram; Figure 2 is a schematic diagram of the volt-second principle; Figure 3 is a control block diagram of the field-oriented control unit of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. The embodiments described in this application are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the spirit of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0023] Embodiment 1 of the present invention provides a motor driving method for improving noise, which is characterized by including: Controlling the inverter through a field-oriented control unit; Real-time collecting the motor frequency at a set period, and judging whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds a set difference threshold; If so, combine the chip idle time and the execution times of each module, and under the constraint of the set frequency, adaptively and real-time increase the frequencies of some modules in the field-oriented control unit; and add a forward difference method to solve the error module in the field-oriented control unit, use this module to correct the angle output by the position and velocity observer module in the field-oriented control unit at the next moment after the frequency increase, and input the corrected angle into the inverse Park module in the field-oriented control unit.

[0024] Difference threshold The setting range of .

[0025] The constraint conditions of the set frequency are specifically: The frequencies of some modules in the field-oriented control unit before increasing the frequency and all other modules except some modules are respectively , ; , Are equal and cannot be an even multiple of the motor base frequency; Obtain the execution times of each module of the field-oriented control unit before increasing the frequency , and the constraint condition of the frequency of some modules after increasing the frequency is:

[0026] In the formula: Is the motor base frequency.

[0027] The field-oriented control unit includes three PI modules, a park module, a clarke module, an inverse Park module, an inverse clarke module, and a position and velocity observer module. The some modules include the inverse Park and inverse clarke modules. The added forward difference method to solve the error module always keeps the same frequency as these some modules.

[0028] It should be noted that the principle of the inverter driving the motor is based on the volt-second principle, also known as the equivalent principle. The input end of the inverter is connected to the DC bus Udc. By controlling the on and off of the switching tubes through the driving chip, a DC voltage with equal amplitude and unequal time can be output to the motor, such as Figure 2Schematic diagram of the volt-second principle. The equivalent curve is ideally a sine curve. However, due to the switching losses of the switching tubes and the computing power of the chip, the switching frequency cannot be infinitely large, which results in the output equivalent curve not being an ideal sine wave, and high-frequency noise audible to the human ear appears during the operation of the motor. Therefore, two working modes are set. In mode 1, the inverter is controlled by the field-oriented control unit. The field-oriented control unit includes three PI modules, a park module, a clarke module, an inverse Park module, an inverse clarke module, and a position and speed observer module. These modules operate at the same frequency. The system output in mode 1 is obtained through sampling and loop calculation. This mode has a large amount of calculation and a long time consumption. It should be noted that in addition to the three PI modules, park module, clarke module, inverse Park module, inverse clarke module, and position and speed observer module, the field-oriented control unit may also include modules such as feedforward, anti-saturation, and SVPWM. The field-oriented control unit using these modules is also within the protection scope of the present invention.

[0029] In mode 2, part of the system output follows mode 1, and the frequency of some modules in the field-oriented control unit is adaptively increased in real time; and a forward difference method for solving errors module is added to the field-oriented control unit to correct the angle output by the position and speed observer module at the next moment after the frequency is increased. The frequency of some modules is increased, and the angle is corrected by simple fitting. This mode has a small amount of calculation and can increase the switching frequency.

[0030] The real-time adaptive increase in the frequency of some modules in the field-oriented control unit is specifically as follows: Obtain the chip idle time at this time and the execution time of some modules in the field-oriented control unit ; Calculate the time for some modules to increase the frequency at this time :

[0031] In the formula: is the frequency of some modules before increasing the frequency, is the frequency of some modules after increasing the frequency; If , then stop increasing the frequency of some modules; if , then increase the frequency of some modules until reaching ; if , then decrease the frequency of some modules until reaching , where is the reserved time for other programs to run normally as set; repeat the above content at the set period.

[0032] Obtaining the chip idle time at this time , specifically as follows: In the main loop, count once every 1 us. Record the total count icnt when the chip starts to execute the algorithm interruption, and clear the count icnt when the execution of the algorithm interruption ends. Then the chip idle time is icnt multiplied by 1 us.

[0033] Adding a forward difference method to solve the error module in the field-oriented control unit, and using this module to correct the angle output by the position and speed observer module at the next moment after the frequency is increased. Specifically as follows: Using the forward difference method to calculate the derivative of the angle output by the position and speed observer module :

[0034] In the formula: , are the angles output by the position and speed observer module at the next moment and the current moment respectively; is the frequency of the previous part of the module before the frequency is increased; The angle output by the position and speed observer module at the next moment after correction is:

[0035] In the formula: is the frequency of the latter part of the module after the frequency is increased.

[0036] Embodiment 2 of the present invention proposes a motor drive system for improving noise using the method described in Embodiment 1 of the present invention, including a field-oriented control unit module, a difference judgment module, a frequency adaptive adjustment module, and a forward difference correction module, characterized in that: Field-oriented control unit module: used to control the inverter through the field-oriented control unit; Difference judgment module: used to collect the motor frequency in real time at a set period, and judge whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds the set difference threshold; Frequency adaptive adjustment module; used to, if so, combine the chip idle time and the execution time of each module, and under the constraint conditions of the set frequency, adaptively increase the frequency of some modules in the field-oriented control unit in real time; Forward difference correction module: used to add a forward difference method to solve the error module in the field-oriented control unit, use this module to correct the angle output by the position and speed observer module in the field-oriented control unit at the next moment after the frequency is increased, and input the corrected angle into the inverse Park module in the field-oriented control unit.

[0037] Embodiment 3 of the present invention provides a device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the steps of a motor driving method for improving noise according to Embodiment 1 of the present invention.

[0038] Embodiment 4 of the present invention provides a computer-readable storage medium storing a computer program, where the computer program, when executed by a processor, uses the steps of a motor driving method for improving noise according to Embodiment 1 of the present invention.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications or equivalent replacements can still be made to the specific embodiments of the present invention, and any modifications or equivalent replacements without departing from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A motor drive method for improving noise, characterized in that, Including: Controlling the inverter through a field-oriented control unit; Collecting the motor frequency in real time at a set period, and judging whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds the set difference threshold; If so, combining the chip idle time and the execution time of each module, and adaptively increasing the frequency of some modules in the field-oriented control unit in real time under the constraint conditions of the set frequency; And adding a forward difference method to solve the error module in the field-oriented control unit, using this module to correct the angle output by the position and speed observer module in the field-oriented control unit at the next moment after the frequency is increased, and inputting the corrected angle into the inverse Park module in the field-oriented control unit.

2. The motor driving method for improving noise according to claim 1, wherein: Difference threshold The setting range is .

3. The motor driving method for improving noise according to claim 1, wherein: The constraint conditions of the set frequency are specifically: Before increasing the frequency, the frequencies of some modules in the field-oriented control unit and all other modules except some modules are respectively , ; , are equal and cannot be an even multiple of the motor base frequency; Obtain the execution time of each module of the field-oriented control unit before increasing the frequency , and the frequencies of some modules after increasing the frequency The constraint conditions are as follows: In the formula: is the fundamental frequency of the motor.

4. The motor driving method for improving noise according to claim 1, wherein: The field-oriented control unit includes three PI modules, a park module, a clarke module, an inverse Park module, an inverse clarke module, and a position and speed observer module. The partial modules include the inverse Park and inverse clarke modules, and the added forward difference method for solving the error module always keeps the same frequency as these partial modules.

5. The motor driving method for improving noise according to any one of claims 1, 3 or 4, wherein: The step of adaptively increasing the frequency of some modules in the field-oriented control unit in real time is specifically: Obtain the chip idle time at this moment and the execution time of some modules in the field-oriented control unit ; Calculate the time for some modules to increase the frequency at this time : Wherein: is the frequency of some modules before the frequency is increased, is the frequency of some modules after the frequency is increased; If , stop increasing the frequency of some modules; if , increase the frequency of some modules until reaching ; if , decrease the frequency of some modules until reaching , where is the reserved time for other programs to run normally as set; repeat the above at the set cycle.

6. The motor driving method for improving noise according to claim 5, wherein: Obtaining the chip idle time at this moment , specifically as follows: Count once every 1 us in the main loop, record the total number icnt at the start of the algorithm interruption executed by the chip, and clear the number icnt at the end of the algorithm interruption execution. Then the idle time of the chip is icnt multiplied by 1 us.

7. The motor driving method for improving noise according to claim 1, wherein: The step of adding a forward difference method to solve the error module in the field-oriented control unit and using this module to correct the angle output by the position and speed observer module at the next moment after the frequency is increased is specifically: Calculating the derivative of the angle output by the position and velocity observer module using the forward difference method : Wherein: and are the angles output by the position and velocity observer modules at the next moment and the current moment, respectively; is the frequency of the previous part of the module before the boosting frequency; The angle output by the position and velocity observer module at the next moment after correction is as follows: In the formula: is the frequency of some modules after the boosting frequency.

8. An improved-noise motor drive system using the method according to any one of claims 1-7, including a field-oriented control unit module, a difference judgment module, a frequency adaptive adjustment module, and a forward difference correction module, wherein: The field-oriented control unit module: used to control the inverter through the field-oriented control unit; The difference judgment module: used to collect the motor frequency in real time at a set period, and judge whether the difference between the motor frequency in the current period and the motor frequency in the previous period, or the difference between the motor frequency in the current period and the set motor frequency exceeds the set difference threshold; The frequency adaptive adjustment module; used to, if so, combine the chip idle time and the execution time of each module, and adaptively increase the frequency of some modules in the field-oriented control unit in real time under the constraint conditions of the set frequency; Forward difference correction module: It is used to add a forward difference method to solve the error module in the field-oriented control unit. This module is used to correct the angle output by the position and speed observer module in the field-oriented control unit at the next moment after the frequency is increased, and input the corrected angle into the inverse Park module in the field-oriented control unit.

9. A device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the steps of a motor drive method for improving noise according to any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the steps of a motor drive method for improving noise according to any one of claims 1 to 7 are used.

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