Common-mode interference suppression method and device for current sampling of permanent magnet synchronous motor

Abstract

The invention provides a common-mode interference suppression method and device for current sampling of a permanent magnet synchronous motor, and relates to the technical field of power electronic electromagnetic interference, and the method comprises the steps: collecting the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating the common-mode current of the three-phase current; determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; and under the condition that the comparison result indicates that the amplitude of the common-mode current accords with the preset threshold value, calculating and adjusting direct-axis current and quadrature-axis current at the next moment based on a prediction compensation algorithm so as to realize suppression of common-mode interference. Through the method provided by the invention, the suppression of the common-mode interference is realized, additional hardware filtering is not needed, the economic cost is low, and meanwhile, the reliability of system operation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic electromagnetic interference, and in particular to a common mode interference suppression method and device for current sampling of a permanent magnet synchronous motor. Background Art

[0002] Common-mode interference has many hazards. Common-mode voltage causes aging of motor insulation, heating, mechanical noise and resonance, etc. Large common-mode voltage will break through the insulating oil film at the stator node to form bearing current, causing the motor to burn out. If the common-mode voltage changes rapidly, the high-frequency and high-amplitude common-mode voltage will cause electromagnetic interference to surrounding equipment. This interference will not only affect the normal operation of other electronic equipment on the power grid, but also reduce the overall performance and reliability of the motor control system.

[0003] The existing technology mainly uses hardware filters to remove common mode interference, which has high economic cost and low efficiency.

[0004] How to economically and efficiently suppress common-mode interference in current sampling of permanent magnet synchronous motors is a technical problem that needs to be solved at present. Summary of the invention

[0005] The present invention provides a common-mode interference suppression method and device for current sampling of a permanent magnet synchronous motor, so as to solve the defects existing in the prior art.

[0006] The present invention provides a common-mode interference suppression method for permanent magnet synchronous motor current sampling, comprising the following steps: Collecting three-phase currents of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating common-mode currents of the three-phase currents; Determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

[0007] According to a common-mode interference suppression method for current sampling of a permanent magnet synchronous motor provided by the present invention, the three-phase current of the permanent magnet synchronous motor is collected based on a preset sampling frequency, and the common-mode current of the three-phase current is calculated, including: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

[0008] According to a common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention, the common-mode current based on the three-phase current determines the corresponding common-mode current amplitude, and compares the common-mode current amplitude with a preset threshold value. After obtaining the comparison result, the method further includes: When the comparison result indicates that the common-mode current amplitude does not meet the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated.

[0009] According to a common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention, the direct-axis current at the next moment is calculated and adjusted based on the prediction compensation algorithm, which is implemented by the following formula: in, represents the direct axis current at the next moment, Represents the nth direct-axis current sampling value, Represents the nth direct-axis voltage sampling value, represents the current calculation cycle, represents the direct-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the quadrature-axis inductance, Indicates the nth quadrature-axis current sampling value.

[0010] According to a common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention, the quadrature axis current at the next moment is calculated and adjusted based on the prediction compensation algorithm, which is implemented by the following formula: in, represents the quadrature axis current at the next moment, Indicates the nth quadrature-axis current sampling value, represents the nth quadrature axis voltage sampling value, represents the current calculation cycle, represents the quadrature-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the direct-axis inductance, Represents the nth direct-axis current sampling value, Represents the rotor flux.

[0011] The present invention also provides a common-mode interference suppression device for permanent magnet synchronous motor current sampling, comprising the following modules: An acquisition module, used to acquire the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculate the common mode current of the three-phase current; A comparison module, used to determine a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compare the common-mode current amplitude with a preset threshold to obtain a comparison result; The adjustment module is used to calculate and adjust the direct-axis current and the quadrature-axis current at the next moment based on the prediction compensation algorithm when the comparison result indicates that the common-mode current amplitude meets the preset threshold value, so as to suppress the common-mode interference.

[0012] According to a common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention, the acquisition module is specifically used for: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

[0013] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor as described in any one of the above methods is implemented.

[0014] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor as described in any one of the above methods is implemented.

[0015] The present invention also provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor, the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor as described in any one of the above methods is implemented.

[0016] The present invention provides a common-mode interference suppression method and device for current sampling of a permanent magnet synchronous motor, which collects the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculates the common-mode current of the three-phase current; determines the corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compares the common-mode current amplitude with a preset threshold to obtain a comparison result; when the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on a prediction compensation algorithm to achieve common-mode interference suppression. It can be seen that the present invention samples the three-phase current at a high speed, identifies common-mode interference, and after identifying the existence of common-mode interference, achieves common-mode interference suppression through prediction compensation, without the need for additional hardware filtering, with low economic cost, and at the same time improves the reliability of system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a flow chart of a common-mode interference suppression method for current sampling of a permanent magnet synchronous motor provided by the present invention.

[0019] Figure 2 It is an overall architecture diagram of the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention.

[0020] Figure 3 It is a structural schematic diagram of a common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention.

[0021] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Before describing the method of the present invention in detail, the terms involved in the present invention are first explained schematically.

[0024] Permanent Magnet Synchronous Motor, referred to as PMSM, is a synchronous motor that uses permanent magnets to establish an excitation magnetic field.

[0025] Common mode interference means that the interference voltage has the same amplitude on the signal line and its return line (generally called the signal ground line). The voltage here takes any nearby object (the earth, metal chassis, reference ground plate, etc.) as the reference potential, and the interference current loop flows in the loop formed by the conductor and the reference object.

[0026] Combine the following Figure 1-Figure 4The present invention describes a common mode interference suppression method and device for current sampling of a permanent magnet synchronous motor.

[0027] Figure 1 is a flow chart of a common mode interference suppression method for current sampling of a permanent magnet synchronous motor provided by the present invention, such as Figure 1 As shown, the method includes the following: Step 100: Collect the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculate the common mode current of the three-phase current.

[0028] It should be noted that Figure 2 is an overall architecture diagram of the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention, such as Figure 2 As shown, the present invention realizes the common-mode interference suppression of permanent magnet synchronous motor current sampling based on the sampler, common-mode interference discriminator and predictive compensator. The above-mentioned sampler, common-mode interference discriminator and predictive compensator are all specific logic execution modules, not hardware structures. For the three-phase current of the permanent magnet synchronous motor, the sampler plays a high-speed acquisition function; the common-mode interference discriminator plays a function of identifying common-mode interference; when the common-mode interference is identified, the predictive compensator realizes the suppression of the common-mode interference through predictive compensation.

[0029] Specifically, step 100 collects the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculates the common mode current of the three-phase current, including: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

[0030] It should be noted that ADC (Analog-to-Digital Converter) is an electronic device that converts continuously changing analog signals into discrete digital signals. In the process of sampling the three-phase current Ia (A phase current), Ib (B phase current), and Ic (C phase current), the main function of ADC is to convert the analog current signal output by the current sensor into a digital signal for subsequent processing and analysis by a microprocessor or digital signal processor (DSP).

[0031] In this embodiment, the main working mode of the sampler is to use ADC to sample the three-phase currents Ia, Ib, and Ic at high speed. When sampling the three-phase currents Ia, Ib, and Ic, three independent ADC channels or modules are usually used, corresponding to the three-phase currents respectively. This ensures that the values ​​of the three-phase currents are sampled simultaneously or almost simultaneously, thereby accurately reflecting the actual operating status of the motor or power system. Set the high-speed sampling frequency, and select the highest possible sampling frequency without distortion of the sampling. For example, if the system allows a sampling frequency of up to 500kHz, Ia, Ib, and Ic are sampled at a high speed of 500kHz. However, too high a sampling frequency may increase the burden on hardware resources and computing power. Therefore, it is necessary to reasonably select the sampling frequency while meeting the accuracy requirements.

[0032] Furthermore, when calculating the common-mode current, it is necessary to ensure that the sampling of the three-phase current is synchronized to avoid errors caused by asynchronous sampling. In addition, it is also necessary to consider the impact of factors such as the zero drift and gain error of the current sensor on the measurement results.

[0033] Specifically, in an ideal situation, if the three-phase currents are completely balanced (i.e., equal in magnitude and 120 degrees out of phase), Icom should be zero. However, in practical applications, Icom may not be zero due to various reasons (such as unbalanced load, current sensor error, etc.).

[0034] In this embodiment, the main working principle of the common mode interference identifier is: collect three-phase currents simultaneously, and define the common mode current Icom = Ia + Ib + Ic. Under normal circumstances, Icom = 0; when there is common mode interference, Icom ≠ 0, and the prediction compensator starts to work.

[0035] Step 200: Determine a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compare the common-mode current amplitude with a preset threshold to obtain a comparison result.

[0036] It should be noted that the amplitude of the common-mode current refers to its maximum value or oscillation amplitude. It is an important parameter to describe the size of the common-mode current. For example, if Icom suddenly increases, it may indicate that the motor is at fault or in an abnormal state. A threshold for the common-mode current amplitude is preset, and this threshold should be able to reflect the boundary between the normal operation and abnormal state of the motor. The calculated common-mode current amplitude is compared with the preset threshold. If the common-mode current amplitude meets the preset threshold, it indicates that the motor may be at fault or in an abnormal state; if the common-mode current amplitude does not meet the preset threshold, it indicates that the motor is in normal operation.

[0037] Specifically, the setting of the preset threshold should be determined according to the specific model and operating specifications of the permanent magnet synchronous motor. At the same time, it is also necessary to consider the impact of factors such as the motor's load condition, working environment, and fault history on the threshold. If the common-mode current amplitude is within the threshold range, the fault alarm or shutdown protection mechanism is triggered to avoid further damage to the motor or cause more serious faults. If the common-mode current amplitude is not within the threshold range, continue to monitor the operating status of the motor, and adjust the control strategy or optimize system performance as needed.

[0038] Step 300 : When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

[0039] It should be noted that in the field of motors, in order to better understand and control the operating state of the motor, the dq rotating coordinate system is introduced. In this coordinate system, the d-axis represents the direct axis and the q-axis represents the quadrature axis. By converting the mathematical model of the motor into this coordinate system, the decoupling of the d-axis and the q-axis can be achieved, thereby simplifying the control of the motor. The d-axis current is mainly used to control the magnetic flux of the motor, that is, to control the excitation state of the motor. By adjusting the magnitude and direction of the d-axis current, the magnetic flux in the motor can be changed, thereby affecting the output torque and efficiency of the motor. The q-axis current is a current related to the direction of the magnetic flux on the quadrature axis (q-axis) of the motor. Unlike the d-axis current, the q-axis current is mainly used to generate the output torque of the motor. In motor control, it is usually necessary to consider the magnitude and direction of the d-axis current and the q-axis current at the same time to achieve precise control of the motor.

[0040] It should be noted that during vector control, the mathematical model of the permanent magnet synchronous motor in the dq coordinate system is: in, represents the d-axis voltage, represents the q-axis voltage, represents the d-axis current, represents the q-axis current, represents the winding resistance, represents the d-axis inductance, represents the q-axis inductance, represents the rotor angular frequency, Represents the rotor flux.

[0041] In this embodiment, one of the predictive compensators is designed after discretization to calculate and adjust the direct-axis current at the next moment based on the predictive compensation algorithm. The formula is as follows: in, represents the direct axis current at the next moment, Represents the nth direct-axis current sampling value, Represents the nth direct-axis voltage sampling value, represents the current calculation cycle, represents the direct-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the quadrature-axis inductance, Indicates the nth quadrature-axis current sampling value.

[0042] In this embodiment, one of the predictive compensators is designed after discretization to calculate and adjust the quadrature axis current at the next moment based on the predictive compensation algorithm. The formula is as follows: in, represents the quadrature axis current at the next moment, Indicates the nth quadrature-axis current sampling value, represents the nth quadrature axis voltage sampling value, represents the current calculation cycle, represents the quadrature-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the direct-axis inductance, Represents the nth direct-axis current sampling value, Represents the rotor flux.

[0043] Furthermore, in step 200, a corresponding common-mode current amplitude is determined based on the common-mode current of the three-phase current, and the common-mode current amplitude is compared with a preset threshold value. After obtaining the comparison result, the method further includes: When the comparison result indicates that the common-mode current amplitude does not meet the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated.

[0044] Specifically, if the common-mode current amplitude does not exceed the set value, the common-mode interference is considered to be within the controllable range, the prediction compensator does not work, and the calculation is performed in the normal order. and If the common-mode current amplitude exceeds the set value, it is considered that the common-mode interference needs to be suppressed, and the predictive compensator starts to work. and .

[0045] The above is a step description of the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention. From the description of the above steps, it can be seen that according to the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the present invention, the three-phase current of the permanent magnet synchronous motor is collected based on a preset sampling frequency, and the common-mode current of the three-phase current is calculated; the corresponding common-mode current amplitude is determined based on the common-mode current of the three-phase current, and the common-mode current amplitude is compared with the preset threshold to obtain a comparison result; when the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to achieve the suppression of common-mode interference. It can be seen that the present invention samples the three-phase current at a high speed, identifies the common-mode interference, and after identifying the existence of common-mode interference, the common-mode interference is suppressed by prediction compensation, without the need for additional hardware filtering, with low economic cost, and at the same time improving the reliability of system operation.

[0046] The common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention is described below. The common-mode interference suppression device for current sampling of a permanent magnet synchronous motor described below and the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor described above can be referred to each other.

[0047] Figure 3 is a structural schematic diagram of a common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention, such as Figure 3 As shown, the common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention comprises: The acquisition module 301 is used to acquire the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculate the common mode current of the three-phase current; A comparison module 302 is used to determine a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compare the common-mode current amplitude with a preset threshold to obtain a comparison result; The adjustment module 303 is used to calculate and adjust the direct-axis current and the quadrature-axis current at the next moment based on the prediction compensation algorithm when the comparison result indicates that the common-mode current amplitude meets the preset threshold value, so as to suppress the common-mode interference.

[0048] The common-mode interference suppression device for current sampling of a permanent magnet synchronous motor provided by the present invention collects the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculates the common-mode current of the three-phase current; determines the corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compares the common-mode current amplitude with a preset threshold value to obtain a comparison result; when the comparison result indicates that the common-mode current amplitude meets the preset threshold value, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on a prediction compensation algorithm to achieve common-mode interference suppression. It can be seen that the present invention samples the three-phase current at a high speed, identifies the common-mode interference, and after identifying the existence of the common-mode interference, achieves the suppression of the common-mode interference through prediction compensation, without the need for additional hardware filtering, with low economic cost, and at the same time improves the reliability of system operation.

[0049] Based on the above embodiments, in this embodiment, the acquisition module 301 is specifically used for: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

[0050] Based on the above embodiment, in this embodiment, the device further includes a calculation module, which is specifically used to: The common-mode current amplitude corresponding to the common-mode current based on the three-phase current is determined, and the common-mode current amplitude is compared with a preset threshold value. After obtaining the comparison result, if the comparison result indicates that the common-mode current amplitude does not meet the preset threshold value, the direct-axis current and the quadrature-axis current at the next moment are calculated.

[0051] Based on the above embodiment, in this embodiment, the calculation and adjustment of the direct-axis current at the next moment based on the prediction compensation algorithm is implemented by the following formula: in, represents the direct axis current at the next moment, Represents the nth direct-axis current sampling value, Represents the nth direct-axis voltage sampling value, represents the current calculation cycle, represents the direct-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the quadrature-axis inductance, Indicates the nth quadrature-axis current sampling value.

[0052] Based on the above embodiment, in this embodiment, the calculation and adjustment of the quadrature-axis current at the next moment based on the prediction compensation algorithm is implemented by the following formula: in, represents the quadrature axis current at the next moment, Indicates the nth quadrature-axis current sampling value, represents the nth quadrature axis voltage sampling value, represents the current calculation cycle, represents the quadrature-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the direct-axis inductance, Represents the nth direct-axis current sampling value, Represents the rotor flux.

[0053] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4 As shown, the electronic device may be a robot or other electronic device, and the electronic device may include: a processor 410, a communications interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communications interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 may call the logic instructions in the memory 430 to execute the common-mode interference suppression method for permanent magnet synchronous motor current sampling, including: Collecting three-phase currents of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating common-mode currents of the three-phase currents; Determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

[0054] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0055] On the other hand, the present invention further provides a computer program product, the computer program product comprising a computer program, the computer program can be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the above methods, including: Collecting three-phase currents of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating common-mode currents of the three-phase currents; Determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

[0056] In another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented when the computer program is executed by a processor to execute the common-mode interference suppression method for permanent magnet synchronous motor current sampling provided by the above methods, including: Collecting three-phase currents of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating common-mode currents of the three-phase currents; Determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

[0057] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0058] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A common mode interference suppression method for permanent magnet synchronous motor current sampling, characterized in that: include: Collecting three-phase currents of the permanent magnet synchronous motor based on a preset sampling frequency, and calculating common-mode currents of the three-phase currents; Determining a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and comparing the common-mode current amplitude with a preset threshold to obtain a comparison result; When the comparison result indicates that the common-mode current amplitude meets the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated and adjusted based on the prediction compensation algorithm to suppress the common-mode interference.

2. The common mode interference suppression method for permanent magnet synchronous motor current sampling according to claim 1 is characterized in that: The method of collecting the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency and calculating the common mode current of the three-phase current includes: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

3. The common mode interference suppression method for permanent magnet synchronous motor current sampling according to claim 1 is characterized in that: After determining the corresponding common-mode current amplitude based on the common-mode current of the three-phase current and comparing the common-mode current amplitude with a preset threshold value to obtain a comparison result, the method further includes: When the comparison result indicates that the common-mode current amplitude does not meet the preset threshold, the direct-axis current and the quadrature-axis current at the next moment are calculated.

4. The common mode interference suppression method for permanent magnet synchronous motor current sampling according to claim 1 is characterized in that: The calculation and adjustment of the direct-axis current at the next moment based on the prediction compensation algorithm is implemented by the following formula: in, represents the direct axis current at the next moment, Represents the nth direct-axis current sampling value, Represents the nth direct-axis voltage sampling value, represents the current calculation cycle, represents the direct-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the quadrature-axis inductance, Indicates the nth quadrature-axis current sampling value.

5. The common mode interference suppression method for permanent magnet synchronous motor current sampling according to claim 4 is characterized in that: The calculation and adjustment of the quadrature axis current at the next moment based on the prediction compensation algorithm is implemented by the following formula: in, represents the quadrature axis current at the next moment, Indicates the nth quadrature-axis current sampling value, represents the nth quadrature axis voltage sampling value, represents the current calculation cycle, represents the quadrature-axis inductance, represents the winding resistance, Indicates the nth rotor angular frequency Sample value, represents the direct-axis inductance, Represents the nth direct-axis current sampling value, Represents the rotor flux.

6. A common mode interference suppression device for permanent magnet synchronous motor current sampling, characterized in that: include: An acquisition module, used to acquire the three-phase current of the permanent magnet synchronous motor based on a preset sampling frequency, and calculate the common mode current of the three-phase current; A comparison module, used to determine a corresponding common-mode current amplitude based on the common-mode current of the three-phase current, and compare the common-mode current amplitude with a preset threshold to obtain a comparison result; The adjustment module is used to calculate and adjust the direct-axis current and the quadrature-axis current at the next moment based on the prediction compensation algorithm when the comparison result indicates that the common-mode current amplitude meets the preset threshold value, so as to suppress the common-mode interference.

7. The common mode interference suppression device for permanent magnet synchronous motor current sampling according to claim 6, characterized in that: The acquisition module is specifically used for: Synchronously collect the A-phase current, B-phase current and C-phase current of the permanent magnet synchronous motor based on a preset sampling frequency; The sum of the A-phase current, the B-phase current and the C-phase current is calculated to obtain the common mode current of the three-phase current.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the common-mode interference suppression method for permanent magnet synchronous motor current sampling as described in any one of claims 1 to 5 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor as claimed in any one of claims 1 to 5 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the common-mode interference suppression method for current sampling of a permanent magnet synchronous motor as claimed in any one of claims 1 to 5 is implemented.

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