Motor and method, device for suppressing noise of motor, motor controller, storage medium

Abstract

The application discloses a motor and a noise suppression method, device, motor controller and storage medium thereof, wherein the motor noise suppression method comprises the following steps: when it is determined that the noise generated by the motor is electromagnetic noise, acquiring a noise frequency and a current harmonic frequency output by a frequency converter; determining the relationship between the noise frequency and the current harmonic frequency; when the noise frequency and the current harmonic frequency are in an integer multiple relationship, adjusting the modulation algorithm of the frequency converter by adding an anti-harmonic source to reduce the output harmonic of the frequency converter. The method can reduce high-order harmonics in the output harmonic, thereby reducing the electromagnetic noise.

Description

Technical Field

[0001] This application relates to the field of motor control technology, and in particular to a motor and its noise suppression method, device, motor controller, and storage medium. Background Technology

[0002] Motor noise includes three types: mechanical noise, electromagnetic noise, and aerodynamic noise. For high-voltage variable frequency direct-drive asynchronous motors with a rated voltage of 6 / 10kV and a rated frequency of 60Hz or higher, the electromagnetic noise may become abnormally high at a certain frequency point, exceeding the allowable value of national or industry standards, due to changes in the motor's magnetic circuit, air gap, and pole pitch as the operating frequency and carrier frequency increase. There are generally two methods to solve this problem: Method 1 is to adjust the number of slots and pole pitch of the motor's squirrel-cage stator and rotor; Method 2 is to increase the inverter's carrier frequency to avoid the stator core's inherent resonance frequency. Method 1 requires multiple attempts, is time-consuming and labor-intensive, and the results are not always ideal; Method 2, by significantly increasing the carrier frequency, not only increases the content of other higher harmonics but also increases the switching losses of the switching transistors, increases the inverter's heat generation, and reduces efficiency. Therefore, when selecting switching transistors, it is necessary to consider increasing a certain margin or considering the heat dissipation structure design of the power unit. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, the first objective of this invention is to propose a method for suppressing motor noise. This method involves adjusting the modulation algorithm of the frequency converter by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, thereby reducing higher-order harmonics in the output harmonics and thus reducing electromagnetic noise.

[0004] A second objective of this invention is to provide a computer-readable storage medium.

[0005] The third objective of this invention is to provide a motor controller.

[0006] The fourth objective of this invention is to provide a motor noise suppression device.

[0007] The fifth objective of this invention is to provide an electric motor.

[0008] To achieve the above objectives, a motor noise suppression method is proposed according to a first aspect of the present invention, comprising: when it is determined that the noise generated by the motor is electromagnetic noise, acquiring the noise frequency and the current harmonic frequency output by the frequency converter; determining the relationship between the noise frequency and the current harmonic frequency; when the noise frequency and the current harmonic frequency are integer multiples of each other, adjusting the modulation algorithm of the frequency converter by adding an antiharmonic source to reduce the output harmonics of the frequency converter.

[0009] According to the motor noise suppression method of this invention, when the noise generated by the motor is non-electromagnetic noise, it is necessary to investigate from the mechanical and aerodynamic aspects of the motor, as it cannot be improved by software methods. Therefore, it is necessary to determine the type of noise. When it is determined that the noise generated by the motor is electromagnetic noise, the noise frequency and the harmonic frequency of the current output by the frequency converter are obtained, and the relationship between the noise frequency and the harmonic frequency is determined. When the noise frequency and the harmonic frequency are integer multiples of each other, the modulation algorithm of the frequency converter is adjusted by adding an antiharmonic source to reduce the output harmonics of the frequency converter. Thus, when the noise frequency and the harmonic frequency are integer multiples of each other, the source of electromagnetic noise is high-order harmonics. Therefore, by adding an antiharmonic source in the modulation algorithm of the frequency converter, the high-order harmonics in the output harmonics can be reduced, thereby reducing electromagnetic noise. This eliminates the need for multiple adjustments to the mechanical structure of the motor, as well as the need to redesign the power unit or the overall heat dissipation system, or to increase the capacity of the frequency converter.

[0010] According to one embodiment of the present invention, determining that the noise generated by the motor is electromagnetic noise includes: when the detected noise decibel value generated by the motor is greater than a preset threshold, using the voltage-frequency ratio separation control method of the frequency converter to determine the relationship between the noise and the output voltage of the frequency converter; and determining that the noise generated by the motor is electromagnetic noise based on the relationship between the noise and the output voltage of the frequency converter.

[0011] According to one embodiment of the present invention, while keeping the motor speed constant, the output voltage of the frequency converter is reduced, and when the noise changes with the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

[0012] According to one embodiment of the present invention, the modulation algorithm of the frequency converter is adjusted by adding an antiharmonic source, including: determining the harmonic information output by the frequency converter; determining the antiharmonic source according to the harmonic information, and adding the antiharmonic source during the modulation process of the frequency converter.

[0013] According to one embodiment of the present invention, determining an antiharmonic source based on harmonic information includes: determining the most abundant higher harmonic based on the harmonic information, and adjusting the timing and interval length of the trigger pulse based on the higher harmonic to generate an antiharmonic source.

[0014] According to one embodiment of the present invention, an antiharmonic source is added to the pulse width modulation of the frequency converter at the point of maximum noise.

[0015] According to one embodiment of the present invention, the frequency of the antiharmonic source is the same as the frequency of the most abundant higher harmonic.

[0016] According to one embodiment of the present invention, when the noise frequency and the current harmonic frequency are not integer multiples of each other, the method further includes: issuing a motor noise suppression prompt message, wherein the motor noise suppression prompt message is used to indicate that the number of slots of the stator and rotor of the motor and the pole pitch need to be adjusted.

[0017] To achieve the above objectives, a computer-readable storage medium is provided according to a second aspect of the present invention, on which a motor noise suppression program is stored, which, when executed by a processor, implements the motor noise suppression method of any of the foregoing embodiments.

[0018] According to the computer-readable storage medium of the present invention, by executing the computer program of the above-described motor noise suppression method, the modulation algorithm of the frequency converter is adjusted by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, thereby reducing the high-order harmonics in the output harmonics and thus reducing electromagnetic noise.

[0019] To achieve the above objectives, a motor controller is provided according to a third aspect of the present invention, including a memory, a processor, and a motor noise suppression program stored in the memory and executable on the processor. When the processor executes the motor noise suppression program, it implements the motor noise suppression method of any of the foregoing embodiments.

[0020] According to an embodiment of the present invention, the motor controller executes a computer program for the above-described motor noise suppression method through a processor. By adjusting the modulation algorithm of the frequency converter by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, the high-order harmonics in the output harmonics are reduced, thereby reducing electromagnetic noise.

[0021] To achieve the above objectives, a motor noise suppression device is provided according to a fourth aspect of the present invention, comprising: an acquisition module, configured to acquire the noise frequency and the harmonic frequency of the current output by the frequency converter when it is determined that the noise generated by the motor is electromagnetic noise; a determination module, configured to determine the relationship between the noise frequency and the harmonic frequency; and a suppression module, configured to adjust the modulation algorithm of the frequency converter by adding an antiharmonic source when the noise frequency and the harmonic frequency are integer multiples of each other, so as to reduce the output harmonics of the frequency converter.

[0022] According to the motor noise suppression device of this embodiment, when the noise generated by the motor is non-electromagnetic noise, it is necessary to investigate from the mechanical and aerodynamic aspects of the motor, as it cannot be improved by software methods. Therefore, it is necessary to determine the type of noise. When the noise generated by the motor is determined to be electromagnetic noise, the acquisition module acquires the noise frequency and the harmonic frequency of the current output by the frequency converter. The determination module determines the relationship between the noise frequency and the current harmonic frequency. When the noise frequency and the current harmonic frequency are integer multiples of each other, the suppression module adjusts the modulation algorithm of the frequency converter by adding an antiharmonic source to reduce the output harmonics of the frequency converter. Thus, when the noise frequency and the current harmonic frequency are integer multiples of each other, the source of electromagnetic noise is high-order harmonics. Therefore, by adding an antiharmonic source in the modulation algorithm of the frequency converter, the high-order harmonics in the output harmonics can be reduced, thereby reducing electromagnetic noise. This eliminates the need for multiple adjustments to the mechanical structure of the motor, as well as the need to redesign the power unit or the overall heat dissipation system, or to increase the capacity of the frequency converter.

[0023] To achieve the above objectives, a motor is provided according to a fifth aspect embodiment of the present invention, including the aforementioned motor controller or the aforementioned motor noise suppression device.

[0024] According to an embodiment of the present invention, by employing the above-described motor controller or motor noise suppression device, when the noise frequency and the current harmonic frequency are in an integer multiple relationship, the modulation algorithm of the frequency converter is adjusted by adding an antiharmonic source to reduce the high-order harmonics in the output harmonics, thereby reducing electromagnetic noise.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] Figure 1 This is a schematic flowchart of a motor noise suppression method according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the process for determining the noise type according to an embodiment of the present invention;

[0028] Figure 3 This is a flowchart illustrating the adjustment of the modulation algorithm of a frequency converter by adding an antiharmonic source according to an embodiment of the present invention;

[0029] Figure 4 This is a flowchart illustrating a motor noise suppression method according to a specific embodiment of the present invention;

[0030] Figure 5 This is a system schematic diagram of a motor controller according to an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of a motor noise suppression device according to an embodiment of the present invention. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] The following description, with reference to the accompanying drawings, describes an embodiment of the present invention, including a motor, a noise suppression method and apparatus, a motor controller, and a storage medium.

[0034] Figure 1 This is a schematic flowchart of a motor noise suppression method according to an embodiment of the present invention. Figure 1 As shown, the motor noise suppression method includes the following steps:

[0035] S101, when it is determined that the noise generated by the motor is electromagnetic noise, the noise frequency and the harmonic frequency of the current output by the frequency converter are obtained.

[0036] Specifically, the noise generated by a motor includes electromagnetic noise and non-electromagnetic noise. Electromagnetic noise can be improved through software control; non-electromagnetic noise, such as mechanical noise and aerodynamic noise, requires investigation from the motor's mechanical and aerodynamic aspects and cannot be improved by software. Therefore, when the noise generated by the motor is determined to be electromagnetic noise, the noise frequency and the harmonic frequency of the inverter's output current are obtained, and the noise generated by the motor is improved through software.

[0037] It should be noted that noise frequencies can be obtained using a noise meter, while current harmonic frequencies can be obtained using a power analyzer.

[0038] In some embodiments, such as Figure 2 As shown, the noise generated by the motor is determined to be electromagnetic noise, including:

[0039] S201 When the noise level generated by the motor exceeds a preset threshold, the inverter uses a voltage-frequency ratio separation control method to determine the relationship between the noise and the output voltage of the inverter.

[0040] Specifically, when the noise level generated by the motor exceeds a preset threshold in decibels, the motor noise is considered excessive and needs to be reduced. Therefore, the type of noise must first be determined. The inverter's voltage-to-frequency ratio control ensures that the motor operates below its rated frequency. To maintain constant motor flux, the ratio of the inverter's output voltage to its output frequency must be kept constant. The inverter's voltage-to-frequency ratio separation control allows for independent control of both output voltage and frequency. While maintaining a constant output frequency, the relationship between noise and the inverter's output voltage is determined.

[0041] S202, based on the relationship between noise and the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

[0042] Specifically, when the output frequency remains constant, changes in the inverter's output voltage will cause changes in the motor's magnetic flux. If the noise generated by the motor is electromagnetic noise, changes in the motor's magnetic flux will affect the electromagnetic noise, resulting in significant noise changes. If the noise generated by the motor is non-electromagnetic noise, such as mechanical noise, changes in the motor's magnetic flux will result in smaller noise changes. Therefore, the type of noise can be determined based on the relationship between the noise and the inverter's output voltage.

[0043] Furthermore, in some embodiments, while keeping the motor speed constant, the output voltage of the frequency converter is reduced, and when the noise changes with the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

[0044] In other words, if the motor speed is kept constant and the output voltage of the frequency converter is reduced, the motor magnetic flux decreases. If the noise decreases significantly, then the motor noise is electromagnetic noise.

[0045] For example, if the motor's rated voltage is 10kV and rated frequency is 120Hz, and the inverter's actual output voltage is 7.5kV when the motor is running at 90Hz, then by reducing the inverter's output voltage to 6kV while keeping the motor speed constant, the motor's magnetic flux will change. If the noise decreases significantly, the noise generated by the motor is determined to be electromagnetic noise; if the noise change is not significant, the noise generated by the motor is determined to be non-electromagnetic noise.

[0046] In the above embodiment, by controlling the voltage-frequency ratio separately, the output voltage of the frequency converter is reduced while keeping the motor speed constant. If the noise decreases significantly, the noise generated by the motor is determined to be electromagnetic noise.

[0047] S102, determine the relationship between noise frequency and current harmonic frequency.

[0048] Specifically, the relationship between the noise frequency and the current harmonic frequency can be determined by calculating the ratio of the noise frequency to the current harmonic frequency.

[0049] S103 When the noise frequency and the current harmonic frequency are integer multiples of each other, the modulation algorithm of the frequency converter is adjusted by adding an anti-harmonic source in order to reduce the output harmonics of the frequency converter.

[0050] Specifically, when the noise frequency and the current harmonic frequency are integer multiples of each other, the source of electromagnetic noise is higher harmonics. Therefore, by adding an antiharmonic source in the modulation algorithm of the frequency converter, the frequency of higher harmonics can be changed, and the higher harmonics in the output harmonics can be reduced, thereby reducing electromagnetic noise.

[0051] In some embodiments, such as Figure 3 As shown, the modulation algorithm of the frequency converter is adjusted by adding an anti-harmonic source, including:

[0052] S301 determines the harmonic information output by the frequency converter.

[0053] Specifically, when the electromagnetic noise is at its maximum, the content of each harmonic in the current harmonics is analyzed by a power analyzer to obtain harmonic information.

[0054] S302 determines the antiharmonic source based on harmonic information and adds the antiharmonic source during the modulation process of the frequency converter.

[0055] In other words, based on the content of each harmonic in the current harmonics, the anti-harmonic source that needs to be added is determined, and the anti-harmonic source is added during the SVPWM (Space Vector Pulse Width Modulation) sinusoidal modulation process to reduce the high-order harmonics of the inverter output.

[0056] In some embodiments, determining an antiharmonic source based on harmonic information includes: determining the most abundant higher harmonic based on the harmonic information, and adjusting the timing and interval length of the trigger pulse based on the higher harmonic to generate an antiharmonic source.

[0057] For example, if the most abundant high-order harmonic is determined to be the 5th harmonic based on harmonic information, an antiharmonic source can be generated by adjusting the timing and interval length of the trigger pulses according to the frequency of the 5th harmonic.

[0058] It should be noted that the most abundant high-order harmonics are generally the third order and above.

[0059] In some embodiments, an antiharmonic source is added to the pulse width modulation of the inverter at the frequency of maximum noise.

[0060] Specifically, frequency converters typically employ SVPWM (Sine Wave Pulse Width Modulation) technology, where the output voltage waveform approximates a sine wave due to the inductance of the motor stator. However, as the output frequency increases, the carrier frequency must be increased to reduce overall output harmonics. After the carrier frequency reaches a certain point, when the frequency of high-frequency harmonic components approaches or equals the natural frequency of the stator core, a resonance effect occurs, resulting in significant electromagnetic noise. Therefore, it is necessary to add an anti-harmonic source to the frequency converter's pulse width modulation at the point of maximum noise, i.e., when the noise frequency approaches or equals the natural frequency of the stator core.

[0061] In the above embodiments, adding an antiharmonic source to the pulse width modulation of the frequency converter at the frequency of maximum noise can avoid the resonance point of the stator core's natural frequency, thereby reducing electromagnetic noise.

[0062] In some embodiments, the frequency of the antiharmonic source is the same as the frequency of the most abundant higher harmonic.

[0063] Understandably, the frequency of the antiharmonic source is the same as the frequency of the most abundant higher harmonic, thus achieving the best elimination effect for the most abundant higher harmonic. For example, if the most abundant higher harmonic is the 5th harmonic, and the antiharmonic source is the anti-5th harmonic, then the 5th harmonic in the output harmonics will be significantly reduced, thereby reducing electromagnetic noise.

[0064] In the above embodiments, by adjusting the modulation algorithm of the frequency converter by adding an antiharmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, the high-order harmonics in the output harmonics can be reduced, thus avoiding the resonance point of the stator core's natural frequency and reducing electromagnetic noise. Furthermore, it is not necessary to make multiple adjustments to the mechanical structure of the motor, nor is it necessary to redesign the power unit or the overall heat dissipation or increase the capacity of the frequency converter.

[0065] In some embodiments, when the noise frequency and the current harmonic frequency are not integer multiples of each other, the method further includes: issuing a motor noise suppression prompt message, wherein the motor noise suppression prompt message is used to indicate that the number of slots and pole pitch of the stator and rotor of the motor need to be adjusted.

[0066] Understandably, the small air gap in motors, especially the squirrel-cage windings, makes them prone to generating various harmonics, resulting in significant electromagnetic noise. The intensity of this noise is related to the stator's dynamic stiffness, natural vibration frequency, and acoustic characteristics. When the noise frequency is not an integer multiple of the current harmonic frequency, the source of the electromagnetic noise is the mechanical structure, not higher harmonics. Therefore, issuing motor noise suppression prompts reminds users to adjust the number of slots and pole pitch of the stator and rotor to reduce electromagnetic noise.

[0067] The technical solution of this application will be further described in detail below with reference to specific implementation methods:

[0068] like Figure 4 As shown, the motor noise suppression method includes the following steps:

[0069] S401 detects the decibel level of the noise generated by the motor.

[0070] S402, determine whether the noise decibel value is greater than the preset threshold. If the noise decibel value is greater than the preset threshold, proceed to step S403. If the noise decibel value is less than or equal to the preset threshold, return to step S401.

[0071] The S403 uses a voltage-frequency ratio separation control method to reduce the output voltage of the frequency converter while keeping the motor speed constant.

[0072] S404, determine whether the noise reduction is greater than the preset range. If the noise reduction is less than or equal to the preset range, proceed to step S405. If the noise reduction is greater than the preset range, proceed to step S406.

[0073] S405 indicates that the noise generated by the motor is non-electromagnetic noise, and the source of the noise can be investigated from mechanical or pneumatic aspects.

[0074] S406, the noise generated by the motor is determined to be electromagnetic noise.

[0075] S407, obtains the noise frequency and the current harmonic frequency of the inverter output, and determines the relationship between the noise frequency and the current harmonic frequency.

[0076] S408, determine whether the noise frequency and the current harmonic frequency are integer multiples of each other. If the noise frequency and the current harmonic frequency are not integer multiples of each other, proceed to step S409. If the noise frequency and the current harmonic frequency are integer multiples of each other, proceed to step S410.

[0077] S409 issues a motor noise suppression prompt message to remind the user to adjust the number of slots and pole pitch of the motor stator and rotor.

[0078] S410, the source of electromagnetic noise was determined to be high-order harmonics.

[0079] S411 incorporates an antiharmonic source into the frequency converter's modulation algorithm to reduce higher-order harmonics in the output harmonics.

[0080] In the above embodiments, when it is determined that the noise generated by the motor is electromagnetic noise and the source of the electromagnetic noise is a high-order harmonic, an anti-harmonic source is added to the modulation algorithm of the frequency converter for adjustment, thereby reducing the high-order harmonics in the output harmonics and thus reducing the electromagnetic noise; and when the source of the electromagnetic noise is not a high-order harmonic, a prompt message is issued in a timely manner to remind the user to adjust the number of slots and pole pitch of the stator and rotor of the motor, thereby reducing the noise by changing the mechanical structure.

[0081] In summary, the motor noise suppression method according to the embodiments of the present invention addresses the issue that when the noise generated by the motor is non-electromagnetic noise, it is necessary to investigate from the mechanical and aerodynamic aspects of the motor, as it cannot be improved through software. Therefore, it is necessary to determine the type of noise. When it is determined that the noise generated by the motor is electromagnetic noise, the noise frequency and the harmonic frequency of the current output by the frequency converter are obtained. When the noise frequency and the harmonic frequency of the current are integer multiples of each other, the source of the electromagnetic noise is a higher harmonic. Therefore, by adding an antiharmonic source in the modulation algorithm of the frequency converter, the higher harmonics in the output harmonics can be reduced, thereby reducing electromagnetic noise. This eliminates the need for multiple adjustments to the mechanical structure of the motor, as well as the need to redesign the power unit or the overall heat dissipation or increase the capacity of the frequency converter.

[0082] Corresponding to the above embodiments, embodiments of the present invention also provide a computer-readable storage medium storing a motor noise suppression program thereon, which, when executed by a processor, implements the motor noise suppression method of any of the foregoing embodiments.

[0083] According to the computer-readable storage medium of the present invention, by executing the computer program of the above-described motor noise suppression method, the modulation algorithm of the frequency converter is adjusted by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, thereby reducing the high-order harmonics in the output harmonics and thus reducing electromagnetic noise.

[0084] Corresponding to the above embodiments, embodiments of the present invention also provide a motor controller. For example... Figure 5 As shown, the motor controller 100 includes a memory 110, a processor 120, and a motor noise suppression program stored in the memory 110 and executable on the processor 120. When the processor 120 executes the motor noise suppression program, it implements the motor noise suppression method of any of the aforementioned embodiments.

[0085] According to an embodiment of the present invention, the motor controller executes a computer program for the above-described motor noise suppression method through a processor. By adjusting the modulation algorithm of the frequency converter by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, the high-order harmonics in the output harmonics are reduced, thereby reducing electromagnetic noise.

[0086] Corresponding to the above embodiments, embodiments of the present invention also provide a motor noise suppression device. For example... Figure 6 As shown, the motor noise suppression device includes: an acquisition module 10, a determination module 20, and a suppression module 30.

[0087] The acquisition module 10 is used to acquire the noise frequency and the current harmonic frequency output by the inverter when it is determined that the noise generated by the motor is electromagnetic noise; the determination module 20 is used to determine the relationship between the noise frequency and the current harmonic frequency; and the suppression module 30 is used to adjust the modulation algorithm of the inverter by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, so as to reduce the output harmonics of the inverter.

[0088] In some embodiments, the device further includes a first determining module 20 (not shown), which is configured to: when the noise decibel value generated by the motor is detected to be greater than a preset threshold, determine the relationship between the noise and the output voltage of the frequency converter by means of voltage-frequency ratio separation control of the frequency converter; and determine that the noise generated by the motor is electromagnetic noise based on the relationship between the noise and the output voltage of the frequency converter.

[0089] In some embodiments, while keeping the motor speed constant, the output voltage of the frequency converter is reduced, and when the noise changes with the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

[0090] In some embodiments, the suppression module 30 is further configured to: determine the harmonic information output by the frequency converter; determine the antiharmonic source based on the harmonic information, and add the antiharmonic source during the modulation process of the frequency converter.

[0091] In some embodiments, the suppression module 30 is further configured to: determine the most abundant higher harmonic based on the harmonic information, and adjust the timing and interval length of the trigger pulse based on the higher harmonic to generate an antiharmonic source.

[0092] In some embodiments, an antiharmonic source is added to the pulse width modulation of the inverter at the frequency of maximum noise.

[0093] In some embodiments, the frequency of the antiharmonic source is the same as the frequency of the most abundant higher harmonic.

[0094] In some embodiments, the device further includes a reminder module (not shown), which is used to issue a motor noise suppression reminder message when the noise frequency and the current harmonic frequency are not integer multiples of each other, wherein the motor noise suppression reminder message is used to indicate that the number of slots and pole pitch of the stator and rotor of the motor need to be adjusted.

[0095] It should be noted that the specific implementation of the motor noise suppression device in this embodiment corresponds one-to-one with the specific implementation of the motor noise suppression method in the foregoing embodiments of this invention, and will not be repeated here.

[0096] According to the motor noise suppression device of the present invention, when the noise generated by the motor is non-electromagnetic noise, it is necessary to investigate from the mechanical and aerodynamic aspects of the motor, and it cannot be improved by software methods. Therefore, it is necessary to determine the type of noise. When the noise generated by the motor is determined to be electromagnetic noise, the acquisition module acquires the noise frequency and the harmonic frequency of the current output by the frequency converter. When the noise frequency and the harmonic frequency of the current are integer multiples of each other, the source of electromagnetic noise is a higher harmonic. Therefore, by adding an antiharmonic source in the modulation algorithm of the frequency converter, the higher harmonics in the output harmonics can be reduced, thereby reducing electromagnetic noise. It is not necessary to make multiple adjustments to the mechanical structure of the motor, nor is it necessary to redesign the power unit or the heat dissipation of the whole machine or increase the capacity of the frequency converter.

[0097] Corresponding to the above embodiments, embodiments of the present invention also provide a motor, including the aforementioned motor controller or the aforementioned motor noise suppression device.

[0098] According to an embodiment of the present invention, by employing the above-described motor controller or motor noise suppression device, when the noise frequency and the current harmonic frequency are in an integer multiple relationship, the modulation algorithm of the frequency converter is adjusted by adding an antiharmonic source to reduce the high-order harmonics in the output harmonics, thereby reducing electromagnetic noise.

[0099] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0100] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0101] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] Furthermore, the terms "first," "second," etc., used in the embodiments of this invention are for descriptive purposes only and should not be construed as indicating or implying relative importance, or implicitly specifying the number of technical features indicated in this embodiment. Therefore, features defined with terms such as "first" and "second" in the embodiments of this invention can explicitly or implicitly indicate that the embodiment includes at least one of those features. In the description of this invention, the word "multiple" means at least two or more, such as two, three, four, etc., unless otherwise explicitly specified in the embodiments.

[0103] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for suppressing motor noise, characterized in that, include: Once it is determined that the noise generated by the motor is electromagnetic noise, the noise frequency and the harmonic frequency of the current output by the frequency converter are obtained. Determine the relationship between the noise frequency and the current harmonic frequency; When the noise frequency and the current harmonic frequency are integer multiples of each other, the modulation algorithm of the frequency converter is adjusted by adding an antiharmonic source in order to reduce the output harmonics of the frequency converter. When the noise frequency and the current harmonic frequency are not integer multiples of each other, the method further includes: A motor noise suppression prompt message is issued, wherein the motor noise suppression prompt message is used to indicate that the number of slots and pole pitch of the stator and rotor of the motor need to be adjusted.

2. The method according to claim 1, characterized in that, The noise generated by the motor has been determined to be electromagnetic noise, including: When the noise level generated by the motor is detected to be greater than a preset threshold, the relationship between the noise and the output voltage of the frequency converter is determined by the voltage-frequency ratio separation control method of the frequency converter. Based on the relationship between the noise and the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

3. The method according to claim 2, characterized in that, While keeping the motor speed constant, the output voltage of the frequency converter is reduced, and when the noise changes with the output voltage of the frequency converter, the noise generated by the motor is determined to be electromagnetic noise.

4. The method according to any one of claims 1-3, characterized in that, The modulation algorithm of the frequency converter is adjusted by adding an anti-harmonic source, including: Determine the harmonic information output by the frequency converter; The antiharmonic source is determined based on the harmonic information, and the antiharmonic source is added during the modulation process of the frequency converter.

5. The method according to claim 4, characterized in that, Determining the antiharmonic source based on the harmonic information includes: The most abundant higher harmonic is determined based on the harmonic information, and the timing and interval length of the trigger pulse are adjusted according to the higher harmonic to generate the antiharmonic source.

6. The method according to claim 4, characterized in that, When the difference between the noise frequency and the stator core natural frequency meets a preset range, the antiharmonic source is added to the pulse width modulation of the frequency converter.

7. The method according to claim 5, characterized in that, The frequency of the antiharmonic source is the same as the frequency of the most abundant high-order harmonic.

8. A computer-readable storage medium, characterized in that, It stores a motor noise suppression program, which, when executed by the processor, implements the motor noise suppression method according to any one of claims 1-7.

9. A motor controller, characterized in that, The device includes a memory, a processor, and a motor noise suppression program stored in the memory and executable on the processor. When the processor executes the motor noise suppression program, it implements the motor noise suppression method according to any one of claims 1-7.

10. A motor noise suppression device, characterized in that, include: The acquisition module is used to acquire the noise frequency and the harmonic frequency of the current output by the frequency converter when it is determined that the noise generated by the motor is electromagnetic noise. The determining module is used to determine the relationship between the noise frequency and the current harmonic frequency; The suppression module is used to adjust the modulation algorithm of the frequency converter by adding an anti-harmonic source when the noise frequency and the current harmonic frequency are integer multiples of each other, so as to reduce the output harmonics of the frequency converter. The reminder module is used to issue a motor noise suppression reminder message when the noise frequency and the current harmonic frequency are not integer multiples of each other. The motor noise suppression reminder message is used to indicate that the number of slots and pole pitch of the stator and rotor of the motor need to be adjusted.

11. An electric motor, characterized in that, Includes the motor controller according to claim 9 or the motor noise suppression device according to claim 10.

Images