Harmonic suppression method, device and motor control system

Abstract

The application provides an embodiment belonging to motor control technology, and provides a harmonic suppression method, a device and a motor control system. The method comprises the following steps: acquiring three-phase currents output from an inverter circuit to a motor in real time, and extracting harmonic currents in the three-phase currents; obtaining compensation currents according to the harmonic currents, adjusting the compensation currents according to a preset adjustment threshold, and outputting adjusted compensation currents; and controlling the three-phase currents output from the inverter circuit according to the adjusted compensation currents. The application can effectively suppress harmonic currents and optimize motor control performance.

Description

Technical Field

[0001] This application relates to motor control technology. More specifically, it relates to a harmonic suppression method, apparatus, and motor control system. Background Technology

[0002] Permanent magnet synchronous motors generate electricity through the interaction between the stator coils and the permanent magnet material on the rotor. They consist of core components such as the rotor, stator, housing, and bearings. Due to their advantages such as simple structure, small size, high efficiency, high power factor, high control precision, and high torque density, permanent magnet synchronous motors are gradually becoming one of the mainstream motors in fields such as industrial automation, new energy vehicles, and home appliances.

[0003] However, due to factors such as uneven external load on the motor, eccentricity of some motor structures, nonlinearity of electrical equipment, and non-sinusoidal distortion of the motor rotor magnetic field, harmonic currents are introduced into the motor drive current, causing torque pulsation and vibration noise, increasing motor losses, and deteriorating motor control performance.

[0004] Therefore, how to effectively suppress harmonic currents is an urgent problem to be solved. Summary of the Invention

[0005] This application provides a harmonic suppression method, apparatus, and motor control system, which can effectively suppress harmonic currents and optimize motor control performance.

[0006] In a first aspect, embodiments of this application provide a harmonic suppression method, comprising:

[0007] The three-phase current output from the inverter circuit to the motor is acquired in real time, and the harmonic current in the three-phase current is extracted.

[0008] The compensation current is obtained based on the harmonic current, and the compensation current is adjusted according to a preset adjustment threshold to output the adjusted compensation current.

[0009] The three-phase current output by the inverter circuit is controlled according to the adjusted compensation current.

[0010] In some embodiments of this application, adjusting the compensation current according to a preset adjustment threshold and outputting the adjusted compensation current specifically includes:

[0011] The control ratio is calculated based on the harmonic current and the preset adjustment threshold.

[0012] The adjusted compensation current is calculated based on the compensation current and the control ratio.

[0013] In some embodiments of this application, the adjustment threshold includes an on threshold and a off threshold, and the step of calculating the control ratio based on the harmonic current and the preset adjustment threshold includes:

[0014] If the harmonic current is greater than the activation threshold, the control ratio is calculated based on the harmonic current and the activation threshold.

[0015] If the harmonic current is less than the shutdown threshold, the control ratio is calculated based on the harmonic current and the shutdown threshold.

[0016] If the harmonic current is greater than or equal to the shutdown threshold, and the harmonic current is less than or equal to the activation threshold, the control ratio is 1.

[0017] In some embodiments of this application, if the harmonic current is greater than the activation threshold, a control ratio is calculated based on the harmonic current and the activation threshold, specifically including:

[0018] If the harmonic current is greater than the activation threshold, the ratio of the harmonic current to the activation threshold minus 1 becomes the control ratio;

[0019] If the harmonic current is less than the shutdown threshold, a control ratio is calculated based on the harmonic current and the shutdown threshold, specifically including:

[0020] If the harmonic current is less than the shutdown threshold, the ratio of the harmonic current to the activation threshold is the control ratio.

[0021] In some embodiments of this application, if the harmonic current is greater than the activation threshold, the ratio of the harmonic current to the activation threshold minus 1 becomes the control ratio, specifically including:

[0022] If the d-axis component of the harmonic current is greater than the d-axis activation threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the activation threshold minus 1.

[0023] If the q-axis component of the harmonic current is greater than the q-axis activation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the activation threshold minus 1.

[0024] If the harmonic current is less than the shutdown threshold, a control ratio is calculated based on the harmonic current and the shutdown threshold, specifically including:

[0025] If the d-axis component of the harmonic current is less than the d-axis shut-off threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the shut-off threshold.

[0026] If the q-axis component of the harmonic current is less than the q-axis shutdown threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the shutdown threshold.

[0027] In some embodiments of this application, the extraction of harmonic currents from the three-phase currents includes:

[0028] The d-axis and q-axis components of the three-phase current are bandpass filtered to obtain the d-axis and q-axis components of the harmonic current.

[0029] In some embodiments of this application, the three-phase current of the motor is controlled according to the adjusted compensation current, including:

[0030] The adjusted compensation current is input into the current loop, and the current loop is used to control the three-phase current of the motor.

[0031] In some embodiments of this application, the three-phase current of the motor is controlled according to the adjusted compensation current, including:

[0032] The d-axis component of the predetermined current is summed with the adjusted d-axis compensation current to obtain the d-axis component of the reference current; the q-axis component of the predetermined current is summed with the adjusted q-axis compensation current to obtain the q-axis component of the reference current.

[0033] The three-phase current output from the inverter circuit to the permanent magnet synchronous motor is adjusted based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current.

[0034] In some embodiments of this application, adjusting the three-phase current output from the inverter circuit to the permanent magnet synchronous motor based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current includes:

[0035] The difference between the d-axis component of the reference current and the d-axis component of the three-phase current is calculated to obtain the d-axis current deviation value; the difference between the q-axis component of the reference current and the q-axis component of the three-phase current is calculated to obtain the q-axis current deviation value.

[0036] The d-axis current deviation value and the q-axis current deviation value are respectively processed by proportional-integral processing to obtain the d-axis component and q-axis component of the target voltage;

[0037] The d-axis and q-axis components of the target voltage are transformed to obtain the α-axis and β-axis components of the target voltage in the αβ coordinate system.

[0038] The target voltage is modulated using SVM based on the α-axis and β-axis components in the αβ coordinate system to obtain an SVM signal. The SVM signal is then output to the inverter circuit so that the inverter circuit outputs the target three-phase current corresponding to the target voltage to the permanent magnet synchronous motor.

[0039] Secondly, embodiments of this application provide a harmonic suppression device, comprising:

[0040] The acquisition module is used to acquire the three-phase current output from the inverter circuit to the motor in real time, and extract the harmonic current from the three-phase current;

[0041] The adjustment module is used to obtain a compensation current based on the harmonic current, adjust the compensation current according to a preset adjustment threshold, and output the adjusted compensation current.

[0042] The control module is used to control the three-phase current output by the inverter circuit according to the adjusted compensation current.

[0043] In some embodiments of this application, the adjustment module is specifically used for:

[0044] The control ratio is calculated based on the harmonic current and the preset adjustment threshold.

[0045] The adjusted compensation current is calculated based on the compensation current and the control ratio.

[0046] In some embodiments of this application, the adjustment threshold includes an on threshold and a off threshold, and the adjustment module is further specifically used for:

[0047] If the harmonic current is greater than the activation threshold, the control ratio is calculated based on the harmonic current and the activation threshold.

[0048] If the harmonic current is less than the shutdown threshold, the control ratio is calculated based on the harmonic current and the shutdown threshold.

[0049] If the harmonic current is greater than or equal to the shutdown threshold, and the harmonic current is less than or equal to the activation threshold, the control ratio is 1.

[0050] In some embodiments of this application, the adjustment module is further specifically used for:

[0051] If the harmonic current is greater than the activation threshold, the ratio of the harmonic current to the activation threshold minus 1 becomes the control ratio;

[0052] If the harmonic current is less than the shutdown threshold, a control ratio is calculated based on the harmonic current and the shutdown threshold, specifically including:

[0053] If the harmonic current is less than the shutdown threshold, the ratio of the harmonic current to the activation threshold is the control ratio.

[0054] In some embodiments of this application, the adjustment module is further specifically used for:

[0055] If the d-axis component of the harmonic current is greater than the d-axis activation threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the activation threshold minus 1.

[0056] If the q-axis component of the harmonic current is greater than the q-axis activation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the activation threshold minus 1.

[0057] If the d-axis component of the harmonic current is less than the d-axis shut-off threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the shut-off threshold.

[0058] If the q-axis component of the harmonic current is less than the q-axis shutdown threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the shutdown threshold.

[0059] In some embodiments of this application, the acquisition module is specifically used for:

[0060] The d-axis and q-axis components of the three-phase current are bandpass filtered to obtain the d-axis and q-axis components of the harmonic current.

[0061] In some embodiments of this application, the control module is specifically used for:

[0062] The adjusted compensation current is input into the current loop, and the current loop is used to control the three-phase current of the motor.

[0063] In some embodiments of this application, the control module is further specifically used for:

[0064] The d-axis component of the predetermined current is summed with the adjusted d-axis compensation current to obtain the d-axis component of the reference current; the q-axis component of the predetermined current is summed with the adjusted q-axis compensation current to obtain the q-axis component of the reference current.

[0065] The three-phase current output from the inverter circuit to the permanent magnet synchronous motor is adjusted based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current.

[0066] In some embodiments of this application, the control module is further specifically used for:

[0067] The difference between the d-axis component of the reference current and the d-axis component of the three-phase current is calculated to obtain the d-axis current deviation value; the difference between the q-axis component of the reference current and the q-axis component of the three-phase current is calculated to obtain the q-axis current deviation value.

[0068] The d-axis current deviation value and the q-axis current deviation value are respectively processed by proportional-integral processing to obtain the d-axis component and q-axis component of the target voltage;

[0069] The d-axis and q-axis components of the target voltage are transformed to obtain the α-axis and β-axis components of the target voltage in the αβ coordinate system.

[0070] The target voltage is modulated using SVM based on the α-axis and β-axis components in the αβ coordinate system to obtain an SVM signal. The SVM signal is then output to the inverter circuit so that the inverter circuit outputs the target three-phase current corresponding to the target voltage to the permanent magnet synchronous motor.

[0071] Thirdly, embodiments of this application provide a motor control system, including: an inverter circuit, a motor, and a harmonic suppression device as described above; wherein...

[0072] The inverter circuit is used to output three-phase current to the motor to drive the motor to run;

[0073] The harmonic suppression device is used to suppress harmonics in the current output from the inverter circuit to the motor.

[0074] Fourthly, this application provides an electronic device, including: a processor, and a memory communicatively connected to the processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory to implement the method described above.

[0075] Fifthly, embodiments of this application provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the method described above.

[0076] Sixthly, embodiments of this application provide a computer program product, including a computer program that, when executed by a processor, implements the method described above.

[0077] The harmonic suppression method, apparatus, and motor control system provided in this application acquire the three-phase current output from the inverter circuit to the motor in real time, extracting the harmonic current from the three-phase current; calculate the compensation current based on the harmonic current, and further adjust the compensation current according to the magnitude of the harmonic current and a preset adjustment threshold; control the three-phase current output from the inverter circuit based on the adjusted compensation current to achieve harmonic suppression. Thus, harmonic suppression can be adaptively adjusted according to the magnitude of the harmonic current, achieving stable and reliable harmonic current suppression and effectively improving the motor's control performance. Attached Figure Description

[0078] To more clearly illustrate the implementation methods in the embodiments of this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0079] Figure 1 A schematic flowchart illustrating a harmonic suppression method provided in an embodiment of this application;

[0080] Figure 2 This is a schematic diagram of the process for obtaining the d-axis and q-axis components of three-phase current according to an embodiment of this application.

[0081] Figure 3 A schematic diagram of the process for obtaining harmonic current provided in an embodiment of this application;

[0082] Figure 4 A schematic diagram of the calculation of the control ratio provided in an embodiment of this application;

[0083] Figure 5 A schematic flowchart of another harmonic suppression method provided in an embodiment of this application;

[0084] Figure 6 A schematic flowchart illustrating another harmonic suppression method provided in an embodiment of this application;

[0085] Figure 7 A schematic flowchart illustrating another harmonic suppression method provided in an embodiment of this application;

[0086] Figure 8 This is a schematic diagram of the structure of the harmonic suppression device provided in the embodiments of this application;

[0087] Figure 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0088] To make the objectives, implementation methods and advantages of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the described exemplary embodiments are only some embodiments of this application, and not all embodiments.

[0089] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0090] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclusively include, for example, a product or device that includes a series of components is not necessarily limited to those that are explicitly listed, but may include other components that are not explicitly listed or that are inherent to such product or device.

[0091] First, let me explain the terms used in this application:

[0092] PI controller: A linear controller that uses the control deviation between the given value and the actual output value to form the control quantity by linearly combining the proportional and integral of the deviation, thereby controlling the controlled object.

[0093] Space Vector Pulse Width Modulation (SVPWM or SVM) is a pulse width modulation wave (SVPWM signal or SVM signal) generated by a specific switching mode composed of six power switching elements of a three-phase power inverter circuit. This pulse width modulation wave controls the switching of the inverter circuit, thereby enabling the inverter circuit to generate the required modulated voltage to drive the motor at the required speed or torque.

[0094] ABC coordinate system: refers to a three-phase stationary natural coordinate system.

[0095] αβ coordinate system: refers to a two-phase stationary coordinate system.

[0096] The dq coordinate system refers to the rotor geometric coordinate system (d-axis is the rotor excitation direction), also known as the synchronous rotating coordinate system.

[0097] Permanent magnet synchronous motors generate electricity through the interaction between the stator coils and the permanent magnet material on the rotor. They consist of core components such as the rotor, stator, housing, and bearings. Due to their advantages such as simple structure, small size, high efficiency, high power factor, high control precision, and high torque density, permanent magnet synchronous motors are gradually becoming one of the mainstream motors in fields such as industrial automation, new energy vehicles, and home appliances.

[0098] However, due to factors such as uneven external load on the motor, eccentricity of some motor structures, nonlinearity of electrical equipment, and non-sinusoidal distortion of the motor rotor magnetic field, harmonic currents are introduced into the motor drive current, causing torque pulsation and vibration noise, increasing motor losses, and deteriorating motor control performance.

[0099] Therefore, how to effectively suppress harmonic currents is an urgent problem to be solved.

[0100] The technical solutions of this application will be described in detail below with reference to specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0101] Figure 1 This is a schematic flowchart illustrating a harmonic suppression method provided in this application. The main implementer of this method is a harmonic suppression device. Figure 1 As shown, the method includes the following steps:

[0102] S101. Real-time acquisition of the three-phase current output from the inverter circuit to the motor, and extraction of harmonic current from the three-phase current.

[0103] Specifically, the three-phase current output from the inverter circuit to the motor may introduce harmonic current. The three-phase current output from the inverter circuit to the motor can be measured in real time, and the harmonic current in the three-phase current can be extracted and analyzed, thereby suppressing the harmonic current.

[0104] For example, the motor can be a permanent magnet synchronous motor.

[0105] After transforming the electrical signal to the dq coordinate system, the harmonic signal will exhibit obvious oscillation characteristics on the dq axis. Therefore, by transforming the three-phase current to the dq coordinate system and filtering or performing spectrum analysis on the d-axis and q-axis components of the three-phase current in the dq coordinate system, the harmonic current can be accurately extracted.

[0106] In one possible implementation, obtaining the d-axis and q-axis components of the three-phase current output from the inverter circuit to the permanent magnet synchronous motor in the dq coordinate system includes:

[0107] Transform the three-phase current to the αβ coordinate system to obtain the α-axis and β-axis components of the three-phase current in the αβ coordinate system.

[0108] Transform the α-axis and β-axis components of the three-phase current in the αβ coordinate system to the dq coordinate system to obtain the d-axis and q-axis components of the three-phase current in the dq coordinate system.

[0109] Figure 2 The flowchart illustrating the process of obtaining the d-axis and q-axis components of three-phase current provided in this application embodiment is shown below. Figure 2As shown, the three-phase currents iu, iv, and iw output from the inverter circuit to the permanent magnet synchronous motor belong to the abc coordinate system. The α-axis component i of the three-phase currents in the αβ coordinate system can be calculated using the Clark transformation (also known as the 3s / 2s coordinate transformation) based on the three-phase currents in the abc coordinate system. α With β-axis component i β Furthermore, through the Park transformation (also known as the 2s / 2r coordinate transformation), based on the α-axis component i corresponding to the three-phase current in the αβ coordinate system... α With β-axis component i β The d-axis components i of the three-phase current in the dq coordinate system were calculated. d With q-axis component i q .

[0110] For example, the formulas for calculating the α-axis and β-axis components of the three-phase current in the αβ coordinate system, based on the three-phase current in the abc coordinate system, are as follows:

[0111] iu+iv+iw=0

[0112] i α =iu

[0113]

[0114] The formulas for calculating the d-axis and q-axis components of the three-phase current in the dq coordinate system, based on the α-axis and β-axis components of the three-phase current in the αβ coordinate system, are as follows:

[0115] i d =i α *cos(θ)+i β *sin(θ)

[0116] i q =i α *sin(θ)+i β *cos(θ)

[0117] Where θ is the current angle of the motor rotor.

[0118] In one possible implementation, the current angle θ of the motor rotor can be calculated using a position observer.

[0119] In this embodiment, the three-phase current is first converted to the αβ coordinate system and then to the dq coordinate system, so as to accurately obtain the d-axis component and q-axis component of the three-phase current in the dq coordinate system.

[0120] Furthermore, in one possible implementation, harmonic currents are extracted from the three-phase currents, including:

[0121] The d-axis and q-axis components of the three-phase current are bandpass filtered to obtain the d-axis and q-axis components of the harmonic current.

[0122] Figure 3 This is a schematic diagram of the process for obtaining harmonic current provided in an embodiment of this application, as shown below. Figure 3 As shown, the d-axis component i of the three-phase current can be... d With q-axis component i q The inputs are respectively fed into bandpass filters, and the d-axis components i of the three-phase currents are processed by the bandpass filters. d With q-axis component i q Bandpass filtering is performed separately to obtain the d-axis component I of the harmonic current. dx With q-axis component I qx The transfer function of a bandpass filter can be:

[0123]

[0124] Where f0 is the frequency bandwidth of the bandpass filter, f c Given the center frequency of the bandpass filter, the d-axis component i of the three-phase current after bandpass filtering is... d With q-axis component i q Mid-frequency at f c Signals within the range of ±f0 can pass through, thus allowing the d-axis component i of the three-phase current to be obtained. d With q-axis component i q The d-axis component I of the harmonic current that has the same frequency as the mechanical frequency of the motor dx With q-axis component I qx .

[0125] It should be noted that in practical applications, other methods can also be used to obtain harmonic currents, such as inputting the d-axis and q-axis components of the three-phase current into a high-pass filter or a low-pass filter respectively, without any restrictions on this.

[0126] In this embodiment, the d-axis and q-axis components of the three-phase current are bandpass filtered to accurately obtain the d-axis and q-axis components of the harmonic current, and harmonic suppression is performed based on the d-axis and q-axis components of the harmonic current.

[0127] S102. Obtain the compensation current based on the harmonic current, adjust the compensation current according to the preset adjustment threshold, and output the adjusted compensation current.

[0128] Specifically, after calculating the compensation current based on the harmonic current, the compensation current can be used for harmonic suppression. In one implementation, harmonic suppression can be enabled or disabled based on the magnitude of the harmonic current and a preset adjustment threshold. For example, harmonic suppression is enabled when the harmonic current is greater than the preset adjustment threshold, and disabled when the harmonic current is less than the preset adjustment threshold. However, when the harmonic current changes, the switching between enabling and disabling harmonic suppression may be abrupt. Therefore, to improve motor performance, the compensation current can be further adjusted based on the magnitude of the harmonic current and the preset adjustment threshold, outputting an adjusted compensation current. This allows for adaptive adjustment of harmonic suppression, achieving stable and reliable harmonic current suppression.

[0129] In one possible implementation, the compensation current is adjusted according to a preset adjustment threshold, and the adjusted compensation current is output. Specifically, this includes:

[0130] The control ratio is calculated based on the harmonic current and the preset adjustment threshold.

[0131] The adjusted compensation current is calculated based on the compensation current and the control ratio.

[0132] Specifically, the control ratio is calculated based on the magnitude of the harmonic current and the preset adjustment threshold; the compensation current is adjusted according to the control ratio to obtain the adjusted compensation current.

[0133] For example, the adjusted compensation current can be the product of the compensation current and the control ratio.

[0134] In this embodiment, the control ratio is calculated based on the harmonic current and the preset adjustment threshold, which can effectively adjust the compensation current based on the control ratio.

[0135] In one possible implementation, the adjustment threshold includes an on threshold and an off threshold. Based on the harmonic current and the preset adjustment threshold, a control ratio is calculated, including:

[0136] If the harmonic current is greater than the threshold, the control ratio is calculated based on the harmonic current and the threshold.

[0137] If the harmonic current is less than the shutdown threshold, the control ratio is calculated based on the harmonic current and the shutdown threshold.

[0138] If the harmonic current is greater than or equal to the shut-off threshold, and the harmonic current is less than or equal to the turn-on threshold, the control ratio is 1.

[0139] For example, the activation threshold can be the magnitude of the current fluctuation at the equilibrium point between motor speed fluctuation and torque fluctuation.

[0140] In this embodiment, when the harmonic current is greater than the turn-on threshold, the control ratio is calculated based on the harmonic current and the turn-on threshold; when the harmonic current is less than the turn-off threshold, the control ratio is calculated based on the harmonic current and the turn-off threshold. The compensation current can be accurately adjusted according to the magnitude of the harmonic current to achieve stable and smooth harmonic suppression.

[0141] Furthermore, in one possible implementation, if the harmonic current is greater than the activation threshold, the control ratio is calculated based on the harmonic current and the activation threshold, specifically including:

[0142] If the harmonic current is greater than the threshold, the ratio of the harmonic current to the threshold is reduced by 1 to determine the control ratio.

[0143] If the harmonic current is less than the shutdown threshold, the control ratio is calculated based on the harmonic current and the shutdown threshold, specifically including:

[0144] If the harmonic current is less than the shutdown threshold, the ratio of the harmonic current to the turn-on threshold is the control ratio.

[0145] Specifically, harmonic current I x >Activation threshold I on At that time, the control ratio P = I x / I on -1; Harmonic current I x <Close Threshold I off At that time, the control ratio P = I x / I off .

[0146] In this embodiment, when the harmonic current is greater than the activation threshold or less than the deactivation threshold, the current harmonic suppression can be adaptively activated and deactivated according to the magnitude of the current harmonics by means of proportional activation or deactivation, and the problem of excessive current fluctuation when the harmonic suppression is activated or deactivated can be effectively avoided, so as to achieve stable and reliable harmonic suppression.

[0147] Specifically, corresponding on / off thresholds can be set for the d-axis and q-axis components of the harmonic current, respectively. In one possible implementation, if the harmonic current exceeds the on / off threshold, the ratio of the harmonic current to the on / off threshold is reduced by 1 as a control ratio, specifically including:

[0148] If the d-axis component of the harmonic current is greater than the d-axis threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the threshold minus 1.

[0149] If the q-axis component of the harmonic current is greater than the q-axis threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the threshold minus 1.

[0150] If the harmonic current is less than the shutdown threshold, a control proportion is calculated according to the harmonic current and the shutdown threshold, which specifically includes:

[0151] If the d-axis component of the harmonic current is less than the d-axis shutdown threshold, the d-axis control proportion of the compensation current is the ratio of the d-axis component of the harmonic current to the shutdown threshold;

[0152] If the q-axis component of the harmonic current is less than the q-axis shutdown threshold, the q-axis control proportion of the compensation current is the ratio of the q-axis component of the harmonic current to the shutdown threshold.

[0153] Figure 4 is a schematic flowchart for calculating the control proportion provided in the embodiments of the present application. As shown in Figure 4 , the d-axis turn-on threshold I d-on , the q-axis turn-on threshold I q-on , the d-axis shutdown threshold I d-off , and the q-axis shutdown threshold I q-off can be set, and the adjusted d-axis component I of the compensation current d-comp * is the product of the d-axis component I of the compensation current d-comp and the d-axis control proportion P of the compensation current d , and the adjusted q-axis component I of the compensation current q-comp * is the product of the q-axis component I of the compensation current q-comp and the compensation current.

[0154] Wherein, when the d-axis component I of the harmonic current dx > the d-axis turn-on threshold I d-on , the d-axis control proportion P of the compensation current is calculated d as follows:

[0155]

[0156] When the d-axis component I of the harmonic current dx < the d-axis shutdown threshold I d-off , the d-axis control proportion P of the compensation current is calculated d as follows:

[0157]

[0158] When the d-axis shutdown threshold I d-off ≤ the d-axis component I of the harmonic current dx ≤ the d-axis turn-on threshold I d-on , the d-axis control proportion P of the compensation current d =1.

[0159] When the q-axis component I of the harmonic current qx > the d-axis turn-on threshold I q-on, the q-axis control proportion P of the compensation current is calculated q as follows:

[0160]

[0161] the q-axis component I of the harmonic current qx <d-axis turn-off threshold I q-off , the q-axis control proportion P of the compensation current is calculated q as follows:

[0162]

[0163] q-axis turn-off threshold I q-off ≤ the q-axis component I of the harmonic current qx ≤ q-axis turn-on threshold I q-on , the q-axis control proportion P of the compensation current q = 1.

[0164] Therefore, when the harmonic current is greater than the turn-on threshold, the proportional turn-on manner can be used to realize the adaptive activation of current harmonic suppression along with the magnitude of the own current harmonic; when the harmonic current is less than the turn-off threshold, the proportional turn-off manner can be used to realize the adaptive deactivation of current harmonic suppression along with the magnitude of the own current harmonic, which effectively avoids the problem of excessive current fluctuation when harmonic suppression is turned on or off, and achieves stable and reliable harmonic suppression.

[0165] In this embodiment, corresponding turn-on thresholds and turn-off thresholds are respectively set for the d-axis component and the q-axis component of the harmonic current, so that the d-axis control proportion and the q-axis control proportion of the compensation current can be accurately calculated according to the magnitudes of the d-axis component and the q-axis component of the harmonic current, thereby accurately adjusting the d-axis component and the q-axis component of the compensation current.

[0166] S103. Controlling the three-phase current of the motor according to the adjusted compensation current.

[0167] In a possible implementation, controlling the three-phase current of the motor according to the adjusted compensation current includes:

[0168] Inputting the adjusted compensation current into a current loop, and using the current loop to control the three-phase current of the motor.

[0169] Figure 5 is a schematic flowchart of another harmonic suppression method provided by an embodiment of the present application. As shown in Figure 5 the figure, in the process of controlling the three-phase current output from the inverter circuit to the motor through the current loop, the d-axis component i corresponding to the three-phase current can be acquired in real time d and the q-axis component i q , according to the d-axis component i of the three-phase currentd With q-axis component i q The d-axis component I of the harmonic current is calculated. dx With q-axis component I qx Based on the d-axis component I of the harmonic current dx With q-axis component I qx The d-axis component I of the compensation current can be calculated. d-comp With q-axis component I q-comp ; and, according to the d-axis component I of the harmonic current dx and q-axis component I qx , and the preset d-axis opening threshold I d-on q-axis activation threshold I q-on d-axis closing threshold I d-off q-axis closing threshold I q-off The d-axis control ratio P of the compensation current can be calculated. d q-axis control proportional P q Set the d-axis control ratio P d With the d-axis component I of the compensation current dx Multiplying them together yields the d-axis component I of the adjusted compensation current. d-comp * ; Control the q-axis proportional P q With the q-axis component I of the compensation current qx Multiplying them together yields the q-axis component I of the adjusted compensation current. q-comp * The d-axis component I of the compensation current d-comp * A current loop with q-axis component input is used to achieve stable suppression of harmonic currents.

[0170] It should be noted that steps S101-S103 can be executed multiple times to achieve automatic adjustment of the output current of the inverter circuit to the permanent magnet synchronous motor and effectively suppress harmonic current.

[0171] The harmonic suppression method provided in this application involves acquiring the three-phase current output from the inverter circuit to the motor in real time, extracting the harmonic current from the three-phase current, calculating a compensation current based on the harmonic current, and further adjusting the compensation current according to the magnitude of the harmonic current and a preset adjustment threshold. The adjusted compensation current is then used to control the three-phase current output from the inverter circuit, thereby achieving harmonic suppression. This allows for adaptive adjustment of harmonic suppression based on the magnitude of the harmonic current, achieving stable and reliable harmonic current suppression and effectively improving the motor's control performance.

[0172] Figure 6 This is a schematic flowchart illustrating another harmonic suppression method provided in an embodiment of this application. The main implementer of this method is a harmonic suppression device. Figure 6As shown, the method may include:

[0173] S601. Real-time acquisition of the three-phase current output from the inverter circuit to the motor. Based on the d-axis and q-axis components of the three-phase current in the dq coordinate system, the d-axis and q-axis components of the harmonic current are obtained.

[0174] S602. Based on the d-axis and q-axis components of the harmonic current, obtain the d-axis and q-axis components of the compensation current.

[0175] S603. If the d-axis component of the harmonic current is greater than the d-axis opening threshold, the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the opening threshold minus 1; if the d-axis component of the harmonic current is less than the d-axis closing threshold, the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the closing threshold.

[0176] Otherwise, the d-axis control ratio of the compensation current is 1.

[0177] S604. If the q-axis component of the harmonic current is greater than the q-axis threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the threshold minus 1.

[0178] If the q-axis component of the harmonic current is less than the q-axis shut-off threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the shut-off threshold.

[0179] Otherwise, the q-axis control ratio of the compensation current is 1.

[0180] S605. Based on the d-axis and q-axis components of the compensation current and the d-axis and q-axis control ratios of the compensation current, calculate the adjusted d-axis and q-axis components of the compensation current.

[0181] It should be noted that the specific implementation methods of S601-S605 are as described above, and will not be repeated here.

[0182] S606. Summing the d-axis component of the predetermined current with the adjusted d-axis compensation current yields the d-axis component of the reference current; summing the q-axis component of the predetermined current with the adjusted q-axis compensation current yields the q-axis component of the reference current.

[0183] In some technologies, the actual three-phase current output from the inverter circuit to the permanent magnet synchronous motor is collected, and compared with a predetermined current. Based on the deviation of the three-phase current from the predetermined current, the three-phase current output from the inverter circuit to the permanent magnet synchronous motor is controlled. To suppress harmonics, the predetermined current can be compensated based on a calculated compensation current.

[0184] Specifically, the d-axis component of the predetermined current is summed with the adjusted d-axis compensation current to obtain the d-axis component of the reference current; the q-axis component of the predetermined current is summed with the adjusted q-axis compensation current to obtain the q-axis component of the reference current. Based on the deviation of the three-phase current relative to the reference current, the three-phase current output from the inverter circuit to the permanent magnet synchronous motor is controlled, thereby achieving harmonic suppression.

[0185] S607. Adjust the three-phase current output from the inverter circuit to the permanent magnet synchronous motor based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current.

[0186] In this embodiment, the predetermined current and the adjusted compensation current are summed to obtain the reference current. Based on the reference current, the three-phase current output from the inverter circuit to the permanent magnet synchronous motor can be accurately adjusted, effectively eliminating harmonic currents and thus improving the control performance of the motor.

[0187] In one possible implementation, adjusting the three-phase current output from the inverter circuit to the permanent magnet synchronous motor based on the d-axis and q-axis components of the reference current and the three-phase currents can include:

[0188] The d-axis current deviation value is obtained by subtracting the d-axis component of the reference current from the d-axis component of the three-phase current; the q-axis current deviation value is obtained by subtracting the q-axis component of the reference current from the q-axis component of the three-phase current.

[0189] The d-axis current deviation value and the q-axis current deviation value are processed by proportional-integral processing respectively to obtain the d-axis component and q-axis component of the target voltage;

[0190] The d-axis and q-axis components of the target voltage are transformed to obtain the α-axis and β-axis components of the target voltage in the αβ coordinate system.

[0191] The SVM signal is obtained by performing SVM modulation on the α-axis and β-axis components of the target voltage in the αβ coordinate system. The SVM signal is then output to the inverter circuit so that the inverter circuit outputs the target three-phase current corresponding to the target voltage to the permanent magnet synchronous motor.

[0192] Figure 7 This is a flowchart illustrating another harmonic suppression method provided in an embodiment of this application, as shown below. Figure 7 As shown, the three-phase currents iu, iv, and iw output from the inverter circuit to the permanent magnet synchronous motor (PMSM) are obtained. A 3s / 2s coordinate transformation is performed on the three-phase currents iu, iv, and iw to obtain the α-axis component i of the three-phase currents in the αβ coordinate system. α With β-axis component i β For the α-axis component i of the three-phase current in the αβ coordinate systemα By performing a 2s / 2r coordinate transformation with the β-axis component, the d-axis component i of the three-phase current in the dq coordinate system is obtained. d With q-axis component i q Based on the d-axis component i of the three-phase current d With q-axis component i q The d-axis component I of the harmonic current can be calculated. dx With q-axis component I qx Based on the d-axis component I of the harmonic current dx With q-axis component I qx The d-axis component I of the compensation current can be obtained. d-comp With q-axis component I q-comp According to the d-axis component I of the harmonic current dx and q-axis component I qx With the preset d-axis opening threshold I d-on q-axis activation threshold I q-on d-axis closing threshold I d-off q-axis closing threshold I q-off The d-axis control ratio P of the compensation current can be calculated. d q-axis control proportional P q Set the d-axis control ratio P d With the d-axis component I of the compensation current d-comp Multiply, and control the q-axis proportional P. q With the q-axis component I of the compensation current q-comp Multiplying these two components yields the adjusted d-axis compensation current I. d-comp * With q-axis compensation current I q-comp * The d-axis component I of the predetermined current. d With the adjusted d-axis compensation current I d-comp * Summing these components yields the d-axis component I of the reference current. d *;The q-axis component I of the predetermined current q With the adjusted q-axis compensation current I q-comp * Summing these components yields the q-axis component I of the reference current. q *. The d-axis component of the reference current and the d-axis component i of the three-phase current. d The difference is calculated to obtain the d-axis current deviation value; the q-axis component of the reference current and the q-axis component of the three-phase current are compared. q The difference is calculated to obtain the q-axis current deviation value. The d-axis current deviation value and the q-axis current deviation value are then input into a proportional-integral (PI) controller to obtain the d-axis component V of the target voltage output by the PI controller. d * With q-axis component V q* Based on the d-axis component V of the target voltage d * With q-axis component V q * The α-axis component V of the target voltage is calculated. α With β-axis component V β The formula is as follows:

[0193] V α =cos(θ)·V d * -sin(θ)·V q *

[0194] V β =sin(θ)·V d * +cos(θ)·V q *

[0195] Among them, the d-axis component V of the current target voltage d * With q-axis component V q * and the d-axis component i of the three-phase current d With q-axis component i q By inputting the position observer, you can obtain the current angle θ of the motor rotor output by the position observer.

[0196] The α-axis component V of the target voltage in the αβ coordinate system α With β-axis component V β SVM modulation is performed to obtain an SVM signal, and the SVM signal is output to the inverter circuit so that the inverter circuit outputs the target three-phase current or target three-phase voltage corresponding to the target voltage to the permanent magnet synchronous motor.

[0197] The harmonic suppression method provided in this application involves acquiring the three-phase current output from the inverter circuit to the motor in real time, extracting the harmonic current from the three-phase current, calculating a compensation current based on the harmonic current, and further adjusting the compensation current according to the magnitude of the harmonic current and a preset adjustment threshold. The adjusted compensation current is then used to control the three-phase current output from the inverter circuit, thereby achieving harmonic suppression. This allows for adaptive adjustment of harmonic suppression based on the magnitude of the harmonic current, achieving stable and reliable harmonic current suppression and effectively improving the motor's control performance.

[0198] This application also provides a harmonic suppression device. This device can be a physical device, or it can be implemented through a computer program, such as application software; alternatively, it can be implemented as a medium storing the relevant computer program, such as a USB flash drive or cloud storage; or it can be implemented through a physical device that integrates or installs the relevant computer program, such as a chip or server. Figure 8 This is a schematic diagram of a harmonic suppression device provided in this application. Figure 8 As shown, the device includes:

[0199] The acquisition module 82 is used to acquire the three-phase current output from the inverter circuit to the motor in real time, and extract the harmonic current in the three-phase current;

[0200] The adjustment module 83 is used to obtain a compensation current based on the harmonic current, adjust the compensation current according to a preset adjustment threshold, and output the adjusted compensation current.

[0201] The control module 84 is used to control the three-phase current output by the inverter circuit according to the adjusted compensation current.

[0202] In some embodiments of this application, the adjustment module is specifically used for:

[0203] The control ratio is calculated based on the harmonic current and the preset adjustment threshold.

[0204] The adjusted compensation current is calculated based on the compensation current and the control ratio.

[0205] In some embodiments of this application, the adjustment threshold includes an on threshold and a off threshold, and the adjustment module is further specifically used for:

[0206] If the harmonic current is greater than the activation threshold, the control ratio is calculated based on the harmonic current and the activation threshold.

[0207] If the harmonic current is less than the shutdown threshold, the control ratio is calculated based on the harmonic current and the shutdown threshold.

[0208] If the harmonic current is greater than or equal to the shutdown threshold, and the harmonic current is less than or equal to the activation threshold, the control ratio is 1.

[0209] In some embodiments of this application, the adjustment module is further specifically used for:

[0210] If the harmonic current is greater than the activation threshold, the ratio of the harmonic current to the activation threshold minus 1 becomes the control ratio;

[0211] If the harmonic current is less than the shutdown threshold, a control ratio is calculated based on the harmonic current and the shutdown threshold, specifically including:

[0212] If the harmonic current is less than the shutdown threshold, the ratio of the harmonic current to the activation threshold is the control ratio.

[0213] In some embodiments of this application, the adjustment module is further specifically used for:

[0214] If the d-axis component of the harmonic current is greater than the d-axis activation threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the activation threshold minus 1.

[0215] If the q-axis component of the harmonic current is greater than the q-axis activation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the activation threshold minus 1.

[0216] If the d-axis component of the harmonic current is less than the d-axis shut-off threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the shut-off threshold.

[0217] If the q-axis component of the harmonic current is less than the q-axis shutdown threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the shutdown threshold.

[0218] In some embodiments of this application, the acquisition module is specifically used for:

[0219] The d-axis and q-axis components of the three-phase current are bandpass filtered to obtain the d-axis and q-axis components of the harmonic current.

[0220] In some embodiments of this application, the control module is specifically used for:

[0221] The adjusted compensation current is input into the current loop, and the current loop is used to control the three-phase current of the motor.

[0222] In some embodiments of this application, the control module is further specifically used for:

[0223] The d-axis component of the predetermined current is summed with the adjusted d-axis compensation current to obtain the d-axis component of the reference current; the q-axis component of the predetermined current is summed with the adjusted q-axis compensation current to obtain the q-axis component of the reference current.

[0224] The three-phase current output from the inverter circuit to the permanent magnet synchronous motor is adjusted based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current.

[0225] In some embodiments of this application, the control module is further specifically used for:

[0226] The difference between the d-axis component of the reference current and the d-axis component of the three-phase current is calculated to obtain the d-axis current deviation value; the difference between the q-axis component of the reference current and the q-axis component of the three-phase current is calculated to obtain the q-axis current deviation value.

[0227] The d-axis current deviation value and the q-axis current deviation value are respectively processed by proportional-integral processing to obtain the d-axis component and q-axis component of the target voltage;

[0228] The d-axis and q-axis components of the target voltage are transformed to obtain the α-axis and β-axis components of the target voltage in the αβ coordinate system.

[0229] The target voltage is modulated using SVM based on the α-axis and β-axis components in the αβ coordinate system to obtain an SVM signal. The SVM signal is then output to the inverter circuit so that the inverter circuit outputs the target three-phase current corresponding to the target voltage to the permanent magnet synchronous motor.

[0230] The harmonic suppression device provided in this application embodiment can perform the harmonic suppression method in the above method embodiment, and its implementation principle and technical effect are similar, so they will not be described again here. It should be noted that the above... Figure 8 The division of modules shown is merely illustrative. This application does not limit the division of modules or the naming of modules.

[0231] This application also provides a motor control system, including: an inverter circuit, a motor, and a harmonic suppression device as described above; wherein,

[0232] The inverter circuit is used to output three-phase current to the permanent magnet synchronous motor to drive the motor to run;

[0233] The harmonic suppression device is used to suppress harmonics in the current output from the inverter circuit to the motor.

[0234] The harmonic suppression system provided in this application embodiment can perform the harmonic suppression method in the above method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0235] This application also provides a schematic diagram of the structure of an electronic device, such as... Figure 9 As shown, the electronic device includes:

[0236] The electronic device includes a processor 291 and a memory 292; it may also include a communication interface 293 and a bus 294. The processor 291, memory 292, and communication interface 293 can communicate with each other via the bus 294. The communication interface 293 can be used for information transmission. The processor 291 can invoke logical instructions stored in the memory 292 to execute the methods of the above embodiments.

[0237] Furthermore, the logic instructions in the aforementioned memory 292 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0238] The memory 292, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this application. The processor 291 executes functional applications and data processing by running the software programs, instructions, and modules stored in the memory 292, thereby implementing the methods in the above-described method embodiments.

[0239] The memory 292 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 292 may include high-speed random access memory and may also include non-volatile memory.

[0240] This application also provides a computer-readable storage medium, which may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk. Specifically, the computer-readable storage medium stores program instructions, which are used in the methods described in the above embodiments.

[0241] This application also provides a program product including execution instructions stored in a readable storage medium. At least one control module of a display device can read the execution instructions from the readable storage medium, and the at least one control module executes the execution instructions to cause the display device to implement the handwriting erasure methods provided in the various embodiments described above.

[0242] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0243] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. A harmonic suppression method, characterized in that, include: The three-phase current output from the inverter circuit to the motor is acquired in real time, and the harmonic current in the three-phase current is extracted. The compensation current is obtained based on the harmonic current, and the compensation current is adjusted according to a preset adjustment threshold to output the adjusted compensation current; wherein, the compensation current includes a d-axis component and a q-axis component; the adjustment threshold includes a d-axis on threshold, a q-axis on threshold, a d-axis off threshold, and a q-axis off threshold; If the d-axis component of the harmonic current is greater than the d-axis activation threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the d-axis activation threshold minus 1; if the d-axis component of the harmonic current is less than the d-axis deactivation threshold, then the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the d-axis deactivation threshold; if the d-axis component of the harmonic current is greater than or equal to the d-axis deactivation threshold and less than or equal to the d-axis activation threshold, then the d-axis control ratio of the compensation current is 1. If the q-axis component of the harmonic current is greater than the q-axis activation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the q-axis activation threshold minus 1; if the q-axis component of the harmonic current is less than the q-axis deactivation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the q-axis deactivation threshold; if the q-axis component of the harmonic current is greater than or equal to the q-axis deactivation threshold and less than or equal to the q-axis activation threshold, then the q-axis control ratio of the compensation current is 1. The d-axis component of the adjusted compensation current is the product of the d-axis component of the compensation current and the d-axis control ratio of the compensation current; the q-axis component of the adjusted compensation current is the product of the q-axis component of the compensation current and the q-axis control ratio of the compensation current. The three-phase current output by the inverter circuit is controlled according to the adjusted compensation current.

2. The method according to claim 1, characterized in that, Extracting harmonic currents from the three-phase currents includes: The d-axis and q-axis components of the three-phase current are bandpass filtered to obtain the d-axis and q-axis components of the harmonic current.

3. The method according to claim 1, characterized in that, Controlling the three-phase current of the motor based on the adjusted compensation current includes: The adjusted compensation current is input into the current loop, and the current loop is used to control the three-phase current of the motor.

4. The method according to claim 1, characterized in that, Controlling the three-phase current of the motor based on the adjusted compensation current includes: The d-axis component of the predetermined current is summed with the adjusted d-axis compensation current to obtain the d-axis component of the reference current; the q-axis component of the predetermined current is summed with the adjusted q-axis compensation current to obtain the q-axis component of the reference current. The three-phase current output from the inverter circuit to the permanent magnet synchronous motor is adjusted based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current.

5. The method according to claim 4, characterized in that, The step of adjusting the three-phase current output from the inverter circuit to the permanent magnet synchronous motor based on the d-axis and q-axis components of the reference current and the d-axis and q-axis components of the three-phase current includes: The difference between the d-axis component of the reference current and the d-axis component of the three-phase current is calculated to obtain the d-axis current deviation value; the difference between the q-axis component of the reference current and the q-axis component of the three-phase current is calculated to obtain the q-axis current deviation value. The d-axis current deviation value and the q-axis current deviation value are respectively processed by proportional-integral processing to obtain the d-axis component and q-axis component of the target voltage; The d-axis and q-axis components of the target voltage are transformed to obtain the α-axis and β-axis components of the target voltage in the αβ coordinate system. The target voltage is modulated using SVM based on the α-axis and β-axis components in the αβ coordinate system to obtain an SVM signal. The SVM signal is then output to the inverter circuit so that the inverter circuit outputs the target three-phase current corresponding to the target voltage to the permanent magnet synchronous motor.

6. A harmonic suppression device, characterized in that, include: The acquisition module is used to acquire the three-phase current output from the inverter circuit to the motor in real time, and extract the harmonic current from the three-phase current; An adjustment module is used to obtain a compensation current based on the harmonic current, adjust the compensation current according to a preset adjustment threshold, and output the adjusted compensation current. The compensation current includes a d-axis component and a q-axis component. The adjustment thresholds include a d-axis on threshold, a q-axis on threshold, a d-axis off threshold, and a q-axis off threshold. If the d-axis component of the harmonic current is greater than the d-axis on threshold, the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the d-axis on threshold minus 1. If the d-axis component of the harmonic current is less than the d-axis off threshold, the d-axis control ratio of the compensation current is the ratio of the d-axis component of the harmonic current to the d-axis off threshold. If the d-axis component of the harmonic current is greater than or equal to the d-axis off threshold and less than or equal to the d-axis on threshold, the compensation current... The d-axis control ratio of the current is 1; if the q-axis component of the harmonic current is greater than the q-axis activation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the q-axis activation threshold minus 1; if the q-axis component of the harmonic current is less than the q-axis deactivation threshold, then the q-axis control ratio of the compensation current is the ratio of the q-axis component of the harmonic current to the q-axis deactivation threshold; if the q-axis component of the harmonic current is greater than or equal to the q-axis deactivation threshold and less than or equal to the q-axis activation threshold, then the q-axis control ratio of the compensation current is 1; the adjusted d-axis component of the compensation current is the product of the d-axis component of the compensation current and the d-axis control ratio of the compensation current; the adjusted q-axis component of the compensation current is the product of the q-axis component of the compensation current and the q-axis control ratio of the compensation current. The control module is used to control the three-phase current output by the inverter circuit according to the adjusted compensation current.

7. A motor control system, characterized in that, include: Inverter circuit, motor, and harmonic suppression device as described in claim 6; wherein, The inverter circuit is used to output three-phase current to the motor to drive the motor to run; The harmonic suppression device is used to suppress harmonics in the current output from the inverter circuit to the motor.

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