Motor harmonic suppression method and system and storage medium

Abstract

The invention provides a motor harmonic suppression method and system and a storage medium, and relates to the technical field of motor control, and the method comprises the steps: obtaining the multi-phase current of a motor; performing space vector decoupling transformation on the multi-phase current to obtain a current component of a harmonic XY plane; 6 < K-1 > harmonic waves and 6 < K + 1 > harmonic waves of the current component are converted into 6 < K > harmonic waves, and K is a positive integer; performing normalization processing on 6K-1 harmonic waves and 6K + 1 harmonic waves of the current component based on the 6K harmonic waves to realize amplitude reconstruction; performing six-frequency-multiplication rotation angle conversion on the normalized current component to generate a direct current quantity; generating a compensation voltage based on the DC amount; and injecting the compensation voltage into a control loop of the motor to suppress harmonic waves. The method aims to carry out key suppression on 6K-1 harmonic and 6K + 1 harmonic of a harmonic XY plane, the efficiency of a motor control system is improved, and global harmonic suppression of a double Y30 six-phase motor can be realized.

Description

Technical Field

[0001] This disclosure belongs to the field of motor control technology, specifically relating to a method, system, and storage medium for motor harmonic suppression. Background Technology

[0002] In the control of a dual Y30 six-phase motor, harmonic issues are significant, particularly the fifth and seventh harmonics, which can cause torque pulsation, winding imbalance, and reduced system efficiency. Theoretically, the harmonic components of a dual Y30 six-phase motor in the XY plane are mainly concentrated in the fifth and seventh harmonics. However, in actual motor control, due to factors such as manufacturing processes, higher-order harmonics or non-negligible lower-order harmonics may exist in the XY plane.

[0003] To achieve harmonic suppression, related technologies employ a strategy of independently decoupling the fifth and seventh harmonics. However, this strategy does not address other harmonic orders, thus exhibiting significant limitations when dealing with complex harmonic scenarios. While this method can convert the fifth harmonic to the seventh harmonic during the rotation angle change, it also converts the seventh harmonic into a high-frequency AC component. This requires filtering with a low-pass filter to effectively extract the DC component. Similarly, the rotation angle change of the seventh harmonic introduces fifth-order high-frequency noise, also necessitating filtering. Therefore, in practical applications, this strategy suffers from relatively complex parameter tuning and limitations in the dynamic characteristics and bandwidth of the filter, directly impacting the real-time performance and stability of harmonic suppression. Summary of the Invention

[0004] This disclosure provides a method, system, and storage medium for suppressing motor harmonics, aiming to at least partially solve the technical problem that related technologies are not applicable to complex harmonic scenarios.

[0005] At least one embodiment of this disclosure provides a method for suppressing motor harmonics, including: Obtain the multiphase current of the motor; The multiphase current is subjected to space vector decoupling transformation to obtain the current components of the harmonic XY plane; The 6K-1 and 6K+1 harmonics of the current component are converted into the 6K harmonic, where K≥1; Based on the 6K harmonic, the 6K-1 and 6K+1 harmonics of the current component are normalized to achieve amplitude reconstruction. The normalized current component is subjected to a sixth-harmonic rotation angle transformation to generate a DC current. A compensation voltage is generated based on the DC flow rate; and... The compensation voltage is injected into the control circuit of the motor to suppress harmonics.

[0006] The above-mentioned solution has the following technical advantages: It proposes a general harmonic suppression method applicable to multiphase motors, especially dual Y30 six-phase motors. This method uses coordinate transformation and amplitude reconstruction strategies to uniformly convert the fifth and seventh harmonics into the sixth harmonic, and then converts them into DC components, thereby avoiding the complexity of parameter adjustment and performance degradation caused by relying on filters. At the control strategy level, by applying real-time voltage compensation in the harmonic XY plane, this method can dynamically track and eliminate other order harmonic components while compensating for the fifth and seventh harmonics, ensuring the robustness of harmonic suppression under different operating conditions. Therefore, this method realizes the construction of a global harmonic suppression system in the harmonic XY plane. Furthermore, this method normalizes the amplitude of the 6K-1 and 6K+1 harmonics and further eliminates harmonic residues by using a rotation angle transformation with a sixth harmonic. Finally, the generated compensation signal is injected into the original control loop. The aim is to focus on suppressing the 6K-1 and 6K+1 harmonics in the XY plane to reduce torque ripple, reduce imbalance between the two windings, improve the current control quality, and increase the efficiency of the motor control system. It can also effectively reduce the global harmonics in the VSD control strategy of the dual Y30 six-phase motor.

[0007] In at least one embodiment of the method provided in this disclosure, the current component includes an X-direction current component and a Y-direction current component, K=1, and the step of converting the 6K-1th harmonic and the 6K+1th harmonic of the current component into a 6Kth harmonic includes: The fifth harmonic is obtained based on the difference between the X-direction current component and the Y-direction current component. The seventh harmonic is obtained based on the sum of the X-direction current component and the Y-direction current component. Based on the amplitude difference between the fifth and seventh harmonics, a converted X-direction current component is generated, wherein the amplitude of the converted X-direction current component is positively correlated with the amplitude difference; and, Based on the sum of the amplitudes of the fifth and seventh harmonics, a converted Y-direction current component is generated, wherein the amplitude of the converted Y-direction current component is positively correlated with the sum of the amplitudes, and the converted X-direction current component and the converted Y-direction current component each contain different sixth harmonics.

[0008] The above solution has the following technical advantages: it converts the fifth and seventh harmonics into the sixth harmonic and then into DC, thus avoiding the complexity of parameter adjustment and performance degradation caused by the dependence on traditional filters.

[0009] In at least one embodiment of the method provided in this disclosure, the normalization processing of the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic includes: The converted X-direction current component is normalized based on a sine function of six times the electrical angle to generate the first coefficient; The transformed Y-direction current component is normalized using a cosine function based on six times the electrical angle to generate a second coefficient. Based on the second coefficient and the X-direction current component obtained through space vector decoupling transformation, a normalized X-direction current component is generated; and, Based on the first coefficient and the Y-direction current component obtained through space vector decoupling transformation, a normalized Y-direction current component is generated.

[0010] The above scheme has the following technical effects: it effectively eliminates harmonic residues. If normalization is not performed, the Park transform cannot effectively convert the AC component into a DC component, resulting in a deterioration in the extraction accuracy of the fifth and seventh harmonics.

[0011] In at least one embodiment of the method provided in this disclosure, the normalization process includes a zero-division protection strategy, which is configured to: when the divisor in the normalization process is zero, place the corresponding first coefficient or the second coefficient at a preset value.

[0012] The above scheme has the following technical effects: it enhances the stability and reliability of the normalization process.

[0013] In the method provided in at least one embodiment of this disclosure, the first coefficient is configured as follows: The product of the electric angular velocity of the motor and time is not equal. When, the first coefficient is the ratio of the converted X-direction current component to the sine function of the six-fold electrical angle; and, The product of the electric angular velocity of the motor and time is When the first coefficient is set to zero, it is used to prevent the coefficient from being removed from zero.

[0014] The above solution has the following technical advantages: ensuring that the entire motor harmonic suppression method maintains stability and accuracy under various operating conditions.

[0015] In the method provided in at least one embodiment of this disclosure, the second coefficient is configured as follows: The product of the electric angular velocity of the motor and time is not equal. When, the second coefficient is the ratio of the converted Y-direction current component to the cosine function of the six-fold electrical angle; and, The product of the electric angular velocity of the motor and time is When the second coefficient is zero, it is set to zero to achieve zero-prevention protection.

[0016] The above solution has the following technical advantages: ensuring that the entire motor harmonic suppression method maintains stability and accuracy under various operating conditions.

[0017] In at least one embodiment of the method provided in this disclosure, the DC quantity includes an X-axis DC quantity and a Y-axis DC quantity, and the step of generating a compensation voltage based on the DC quantity includes: The X-axis DC input is controlled in a closed loop by a preset first proportional-integral controller to generate a dynamic compensation voltage in the X-axis; and... The Y-axis DC flow is controlled in a closed loop by a preset second proportional-integral controller to generate a dynamic compensation voltage in the Y-axis.

[0018] The above scheme has the following technical effects: the transformed DC quantity is injected into the original control loop through PI closed-loop control, and the harmonic components other than the fifth and seventh harmonics can be dynamically tracked and suppressed through two proportional-integral controllers.

[0019] In at least one embodiment of the method provided in this disclosure, the space vector decoupling transformation employs a VSD transformation, and the sixth-harmonic rotation angle transformation employs a sixth-harmonic Park transformation; furthermore, the method further includes: By adjusting the coefficients of the first proportional-integral controller and the second proportional-integral controller, independent configuration of the suppression bandwidth for different orders of harmonics can be achieved.

[0020] The above scheme offers the following technical advantages: VSD transformation can clearly identify harmonic components, and the sixth-harmonic Park transformation accurately converts AC signals to a rotating coordinate system, achieving signal decoupling. Furthermore, the scheme allows for customized settings for harmonic suppression of different orders, thereby further optimizing the motor's harmonic suppression effect. At least one embodiment of this disclosure also provides a motor harmonic suppression system, comprising: The signal acquisition unit is configured to acquire the multiphase current of the motor; The signal conversion unit is configured to perform space vector decoupling transformation on the multiphase current to obtain the current components in the harmonic XY plane, and to convert the 6K-1th and 6K+1th harmonics of the current components into a 6Kth harmonic, where K≥1; and, The harmonic processing unit is configured to normalize the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic, and to perform a six-fold frequency rotation angle transformation on the normalized current component to generate a DC component. The harmonic suppression unit is configured to generate a compensation voltage based on the DC quantity; and, The signal injection unit is configured to inject the compensation voltage into the control circuit of the motor to suppress harmonics.

[0021] At least one embodiment of this disclosure also provides a storage medium storing a program or instructions, wherein the program or instructions, when executed by a processor, implement the steps of the method provided in any embodiment of this disclosure.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A flowchart of a motor harmonic suppression method provided for at least one embodiment of this disclosure; Figure 2 A flowchart illustrating a harmonic conversion scheme provided in at least one embodiment of this disclosure; Figure 3 A flowchart illustrating the normalization processing scheme provided in at least one embodiment of this disclosure; Figure 4 A flowchart illustrating a compensation voltage generation scheme provided in at least one embodiment of this disclosure; Figure 5 A flowchart illustrating another motor harmonic suppression method provided in at least one embodiment of this disclosure; Figure 6 A control diagram illustrating an example of a motor harmonic suppression method provided in at least one embodiment of this disclosure; Figure 7 A structural block diagram of a motor harmonic suppression system provided in at least one embodiment of this disclosure; Figure 8 A schematic diagram illustrating the composition of a program product provided for at least one embodiment of this disclosure.

[0025] Figure label: 10- Motor harmonic suppression system; 11- Signal acquisition unit; 12- Signal conversion unit; 13- Harmonic processing unit; 14- Harmonic suppression unit; 15- Signal injection unit; 21- Processor; 22- Memory; 23- Input device; 24- Output device; - time; - Required rotational speed; - Actual rotational speed; - Required torque; XY to XY conversion; DQ to DQ conversion; - Phase a current; - Phase b current; - c-phase current; - Phase U current; - Phase current; - Phase current; - Phase a voltage; - Phase b voltage; - c-phase voltage; - Phase U voltage; - Phase voltage; - Phase voltage; -d-axis current; - q-axis current; - α-axis current; - β-axis current; - X-direction current component; - Y-direction current component; , - Different currents in the zero-sequence plane; - X-axis voltage; - Y-axis voltage; - d-axis voltage; - q-axis voltage; - α-axis voltage; - β-axis voltage; subscript * - Required value; subscript 6 th - 6x frequency. Detailed Implementation

[0026] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the disclosure. Similarly, the following embodiments are only some, not all, embodiments of the present disclosure, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this disclosure.

[0027] The terms "first," "second," and "third" used in the embodiments of this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," and "third" may explicitly or implicitly include at least one of that feature.

[0028] In the description of this disclosure, "multiple" means at least two, such as two or three, unless otherwise expressly and specifically limited.

[0029] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] The terms “comprising” and “having”, and any variations thereof, used in this disclosure are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to such processes, methods, products, or devices.

[0031] The term "dual Y30 six-phase motor" in this disclosure, also known as a dual Y30° six-phase motor, refers to a type of six-phase motor consisting of two sets of windings connected in parallel. "Dual Y30°" and "dual Y30" refer to the 30° phase shift between the two sets of windings, their Y-type connection, and the isolation of their neutral points. A dual Y30 six-phase motor can also be called a dual Y30 dual three-phase motor.

[0032] In the embodiments of this disclosure, the term "VSD transformation" refers to a spatial vector decoupling coordinate transformation that maps the six-phase currents abcuvw to three mutually orthogonal planes: the fundamental aβ plane, the harmonic XY plane, and the zero-sequence plane.

[0033] In the embodiments of this disclosure, the term "fundamental aβ plane" refers to the part corresponding to the first two rows of the VSD transform array, which is mainly composed of fundamental components and participates in the electromechanical energy conversion of the motor.

[0034] In this embodiment of the disclosure, the term "harmonic XY plane" refers to the part corresponding to the middle two rows of the VSD transformation array, which mainly consists of the fifth and seventh harmonics and does not participate in the electromechanical energy conversion of the motor.

[0035] In the embodiments of this disclosure, the term "zero-sequence plane" refers to the part corresponding to the last two rows of the VSD transformation array, which has an output of 0 and does not participate in the electromechanical energy conversion of the motor.

[0036] In the embodiments of this disclosure, the term "Park transformation" refers to transforming the aβ axis from the fundamental aβ plane to the dq axis of the synchronous rotating coordinate system.

[0037] Figure 1 This is a flowchart illustrating a motor harmonic suppression method provided in at least one embodiment of this disclosure. The method is applied to multiphase motors, including but not limited to dual Y30 six-phase motors. Figure 1 As shown, the method may include the following steps S10-S70.

[0038] Step S10: Obtain the multiphase current of the motor.

[0039] Step S20: Perform space vector decoupling transformation on the multiphase current to obtain the current components of the harmonic XY plane.

[0040] Step S30: Convert the 6K-1 and 6K+1 harmonics of the current component into the 6K harmonic, where K is a positive integer.

[0041] Step S40: Normalize the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic to achieve amplitude reconstruction.

[0042] Step S50: Perform a six-fold frequency rotation angle transformation on the normalized current component to generate a DC current.

[0043] Step S60: Generate compensation voltage based on DC flow.

[0044] Step S70: Inject compensation voltage into the motor control circuit to suppress harmonics.

[0045] It should be noted that the above scheme focuses on suppressing the 6K-1 and 6K+1 harmonics, without neglecting other harmonic orders, thus achieving global harmonic suppression. Dual-phase three-phase motors mainly contain the fifth and seventh harmonics, in which case K=1. For other multi-phase motors, which may contain more harmonics of different orders, this method can still be used to effectively suppress harmonics by adjusting the value of K.

[0046] In the above scheme, this disclosure does not limit the method of obtaining the multiphase current in step S10. In practical application scenarios, the multiphase current can be obtained through various sensors, such as current transformers or Hall sensors. These sensors can accurately measure the current value of each phase of the motor and convert it into a signal form suitable for subsequent processing.

[0047] When harmonic suppression is required, the system initiates step S10 to collect the current of each phase of the motor in real time, and performs voltage compensation based on the characteristics of the real-time multiphase current.

[0048] In the above scheme, this disclosure does not limit the spatial vector decoupling transformation scheme in step S20. In practical application scenarios, there are multiple options for the spatial vector decoupling transformation scheme to the harmonic XY plane, such as VSD transformation, which can quickly and accurately extract the current components of the harmonic XY plane. Spatial vector decoupling transformation schemes based on other specific coordinate systems can also be used to meet the needs of different motor control systems.

[0049] When the system executes step S20, it will use the selected space vector decoupling transformation scheme to convert the acquired multiphase current to the harmonic XY plane, thereby accurately extracting the current components of the harmonic XY plane and providing accurate data support for subsequent harmonic suppression operations.

[0050] In the above scheme, this disclosure does not limit the conversion scheme for converting the 6K-1 and 6K+1 harmonics to the 6K harmonic in step S30. For example, the components of the 6K-1 and 6K+1 harmonics can be recombinated and converted through specific mathematical operations and coordinate transformations to present them in the form of the 6K harmonic. Alternatively, a conversion scheme based on signal processing algorithms can be used, which involves filtering and modulating the acquired current signal to achieve the conversion of the 6K-1 and 6K+1 harmonics to the 6K harmonic, thereby meeting the harmonic processing requirements of different motor control systems.

[0051] When the system executes step S30, it will convert the 6K-1 harmonic and 6K+1 harmonic into the 6K harmonic according to the preset conversion strategy, so as to better meet the diverse requirements of different motor control systems for harmonic processing.

[0052] In the above scheme, this disclosure does not limit the normalization processing method used to achieve amplitude reconstruction in step S40. In practical application scenarios, there are various normalization processing strategies to choose from. In addition to the normalization processing strategies provided in the following embodiments, the amplitude of the acquired current signal can also be scaled according to a certain ratio to make it fall within a specific numerical range, such as normalizing the amplitude to the [0,1] interval or the [-1,1] interval, which facilitates subsequent unified amplitude reconstruction calculation. A normalization processing strategy based on statistical characteristics can also be adopted. By calculating the mean, standard deviation, and other statistical quantities of the signal amplitude, the signal amplitude is standardized to give the signal specific statistical distribution characteristics, thereby realizing the normalization operation before amplitude reconstruction to adapt to the accuracy and stability requirements of different motor control systems for amplitude reconstruction.

[0053] When the system executes step S40, it can dynamically select a suitable normalization strategy according to the actual needs of the motor control system, so that the system can better adapt to various complex and ever-changing motor control environments and improve the overall effect of harmonic suppression.

[0054] In the above scheme, this disclosure does not limit the rotation angle transformation scheme for the sixth harmonic in step S50. In practical applications, a coordinate transformation method based on the principle of orthogonal transformation can be used. By constructing a specific orthogonal transformation matrix, the signal can be transformed from the initial coordinate system to the sixth harmonic rotating coordinate system to achieve effective separation and processing of harmonics of specific frequencies. In addition, a coordinate transformation strategy based on complex number operations can be used, utilizing the real and imaginary parts of complex numbers to represent different components of the signal, thereby completing the accurate extraction and suppression of harmonic signals in the sixth harmonic rotating coordinate system.

[0055] When the system executes step S50, it can flexibly and dynamically select the most suitable sixth harmonic rotation angle change scheme according to the specific conditions of the motor control system and the harmonic characteristics, thereby further enhancing the pertinence and effectiveness of harmonic suppression.

[0056] In the above scheme, this disclosure does not limit the scheme of generating compensation voltage based on DC quantity in step S60. In practical applications, a proportional-integral-derivative (PID) control algorithm can be used to dynamically adjust the magnitude of the compensation voltage according to the deviation between the DC quantity and the desired value, so as to achieve fast and accurate suppression of motor harmonics. Alternatively, a fuzzy control algorithm can be used to generate the corresponding compensation voltage based on the fuzzy set of DC quantity and preset fuzzy rules, thereby effectively addressing the uncertainties and nonlinearities in the motor control system and improving the robustness of harmonic suppression.

[0057] When the system executes step S60, it can intelligently and flexibly select the most suitable scheme for generating compensation voltage based on DC flow, taking into account the real-time operating status of the motor control system and the dynamic changes of harmonics.

[0058] In the above scheme, this disclosure does not limit the motor control scheme based on compensation voltage in step S70. In practical applications, the compensation voltage can be superimposed on the initial control voltage of the motor to obtain an adjusted motor control voltage, thereby achieving precise control of the motor and effectively suppressing motor harmonics. Alternatively, advanced intelligent control algorithms, such as neural network control algorithms, can be used to automatically generate optimal motor control commands based on the compensation voltage and the real-time operating parameters of the motor, further improving the effect of motor harmonic suppression and ensuring that the motor can still operate stably and efficiently under complex operating conditions.

[0059] Through steps S10-S70, a complete and scientific method for motor harmonic suppression was established. Residual AC harmonics are eliminated through coordinate transformation and amplitude reconstruction strategies, ensuring the extraction accuracy of the fifth and seventh harmonics. This strategy eliminates the need for filters, avoiding complex tuning processes and reducing the complexity of decoupling the fifth and seventh harmonics in a dual-channel configuration. Given the wide applicability of dual Y30 six-phase motors, this strategy can simultaneously suppress harmonics across the entire XY plane, effectively reducing the fifth and seventh harmonic content in the harmonic plane while also considering other harmonics in the XY plane. This aligns with the multi-harmonic coupling characteristics of dual Y30 six-phase motors, expanding application scenarios. A global harmonic suppression strategy was constructed for the XY plane, enabling dynamic tracking and elimination of other harmonic components while compensating for the fifth and seventh harmonics, ensuring robustness of harmonic suppression under different operating conditions.

[0060] In some embodiments, in order to accurately identify harmonic components, Figure 1 Based on this, the space vector decoupling transformation in step S20 employs VSD transformation. In the process of motor harmonic suppression, VSD transformation can more clearly identify harmonic components, providing a strong basis for the accurate generation of compensation voltage, and helping to improve the accuracy and effectiveness of the entire harmonic suppression method.

[0061] The theory of VSD transformation is introduced below.

[0062] For a dual three-phase motor, the theoretical current is as follows:

[0063] In the formula, This represents the current in phase a. This represents the phase b current. This represents the c-phase current. Represents the u-phase current. Indicates the phase current (v). Indicates the phase current (w). Indicates time, Represents electric angular velocity. Indicates the amplitude of the fundamental frequency. This represents the amplitude of the fifth harmonic. It represents the amplitude of the seventh harmonic.

[0064] The harmonics of a dual three-phase motor mainly include the fifth and seventh harmonics. The VSD transformation can convert these harmonics to the XY harmonic plane. The Clark transform matrix in the VSD transformation... as follows:

[0065] Park transform matrix in VSD transformation as follows:

[0066] Using VSD to perform coordinate transformation on the phase currents of abcuvw, the following results were obtained:

[0067] In the formula, and Represents different currents in the fundamental αβ plane. This represents the X-axis current component in the harmonic XY plane. This represents the Y-axis current component in the harmonic XY plane. and Represents different currents in the zero-sequence plane.

[0068] Figure 2 A flowchart illustrating a harmonic conversion scheme provided in at least one embodiment of this disclosure. Figure 1 Based on this, in order to accurately extract the sixth harmonic, the current components include the X-direction current component and the Y-direction current component, K=1, and, as Figure 2 As shown, step S30 is further refined into the following sub-steps S301-S304.

[0069] Sub-step S301: Obtain the fifth harmonic based on the difference between the X-direction current component and the Y-direction current component.

[0070] Sub-step S302: Obtain the seventh harmonic based on the sum of the X-direction current component and the Y-direction current component.

[0071] Sub-step S303: Based on the difference in amplitude between the fifth and seventh harmonics, a converted X-direction current component is generated, wherein the amplitude of the converted X-direction current component is positively correlated with the difference in amplitude.

[0072] Sub-step S304: Based on the sum of the amplitudes of the fifth and seventh harmonics, generate the converted Y-direction current component, wherein the amplitude of the converted Y-direction current component is positively correlated with the sum of the amplitudes, and the converted X-direction current component and the converted Y-direction current component each contain different sixth harmonics.

[0073] During motor operation, there is a specific correlation between the fifth and seventh harmonics and the sixth harmonic. By using different combinations of X-axis and Y-axis current components, the fifth and seventh harmonics are first obtained, and then the converted X-axis and Y-axis current components are generated based on the difference or sum of their amplitudes. These converted current components contain different sixth harmonic information, thereby achieving accurate extraction of the sixth harmonic and effectively improving the motor's harmonic suppression effect.

[0074] In some embodiments, in order to accurately identify harmonic components, Figure 1 Based on this, the space vector decoupling transformation in step S20 adopts an improved VSD transformation.

[0075] The improved VSD transformation principle is introduced below.

[0076] Novel Park Transform Array as follows:

[0077] In the formula, This indicates the electrical angle value of the motor.

[0078] Using a novel Park transformation matrix The following relationship can be obtained:

[0079] In the formula, This represents the converted X-axis current component. This represents the converted Y-axis current component.

[0080] The above scheme uses a novel Park transform to uniformly convert the fifth and seventh harmonics into the sixth harmonic, and then converts it into a DC signal, avoiding the complexity of parameter adjustment and performance degradation caused by the dependence on traditional filters.

[0081] Figure 3 A flowchart illustrating the normalization processing scheme provided in at least one embodiment of this disclosure. Figure 1 Based on this, in order to generate DC without relying on filters, such as Figure 3 As shown, step S40 is further refined into the following sub-steps S401-S404.

[0082] Sub-step S401: Normalize the converted X-direction current component based on a sine function of six times the electrical angle to generate the first coefficient.

[0083] Sub-step S402: Normalize the converted Y-direction current component based on a cosine function of six times the electrical angle to generate a second coefficient.

[0084] Sub-step S403: Based on the second coefficient and the X-direction current component obtained through space vector decoupling transformation, generate the normalized X-direction current component.

[0085] Sub-step S404: Based on the first coefficient and the Y-direction current component obtained through space vector decoupling transformation, generate the normalized Y-direction current component.

[0086] In this process, sub-steps S401 to S404 normalize the converted X-axis and Y-axis current components using sine and cosine functions at six times the electrical angle, respectively, generating corresponding coefficients. Based on these coefficients and the current components obtained through space vector decoupling transformation, the normalized X-axis and Y-axis current components are then obtained. This approach avoids relying on filters to generate DC current, simplifies the control process, and improves the accuracy and efficiency of current component processing, thus enhancing the motor's harmonic suppression performance.

[0087] In some embodiments, Figure 3 Building upon this foundation, to enhance the stability and reliability of the normalization process, a zero-division protection strategy is included. This strategy is configured such that when the divisor in the normalization process is zero, the corresponding first or second coefficient is set to a preset value. The preset value can be flexibly set according to the actual application scenario and requirements; for example, it can be set to zero or a very small value close to but not zero. This avoids calculation errors caused by division by zero and minimizes the impact on subsequent calculations and processing results. By introducing the zero-division protection strategy, the stability and reliability of the normalization process are further enhanced, ensuring that the entire motor harmonic suppression method can operate normally under various complex working conditions.

[0088] In some embodiments, Figure 3 Based on this, to enhance the stability and reliability of the normalization process, the first coefficient is configured as follows: when the product of the electric angular velocity of the motor and time is not equal to... At that time, the first coefficient is the ratio of the converted X-direction current component to the sine function of six times the electrical angle; and, when the product of the motor's electrical angular velocity and time is... When zero division occurs, the first coefficient is set to zero to achieve zero-division protection. Here, the electrical angle in the sine function of six electrical angles is the product of the motor's electrical angular velocity and time. Through this configuration, the first coefficient can flexibly take values ​​according to different situations involving the product of the motor's electrical angular velocity and time. This ensures accurate calculation under normal operating conditions and timely zeroing in special operating conditions where there is a risk of zero division, thus playing a role in zero-division protection and guaranteeing the stability and accuracy of the entire motor harmonic suppression method.

[0089] In some embodiments, Figure 3 Based on this, to enhance the stability and reliability of the normalization process, the second coefficient is configured as follows: when the product of the electric angular velocity of the motor and time is not equal to... At that time, the second coefficient is the ratio of the converted Y-direction current component to the cosine function of six times the electrical angle; and, when the product of the motor's electrical angular velocity and time is... When zero division occurs, the second coefficient is set to zero to prevent zero division protection. The electrical angle in the cosine function of six times the electrical angle is also the product of the motor's electrical angular velocity and time. This configuration allows the second coefficient to be flexibly determined based on the specific conditions of the product of the motor's electrical angular velocity and time. Under normal operating conditions, the second coefficient can be accurately obtained based on the relationship between the converted Y-direction current component and the cosine function of six times the electrical angle, providing reliable data for subsequent motor harmonic suppression calculations. In special operating conditions where zero division risk may occur, setting the second coefficient to zero in a timely manner effectively prevents zero division, ensuring the stability and accuracy of the entire motor harmonic suppression method under various operating conditions.

[0090] As an exemplary implementation, the X-direction current component obtained through space vector decoupling transformation and Y-axis current component as follows:

[0091] First coefficient x Second coefficient y The acquisition method is as follows:

[0092] In the formula, This represents the converted X-axis current component. This represents the converted Y-axis current component.

[0093] X-direction current component after normalization and the normalized Y-axis current component as follows:

[0094] The above scheme involves a unified harmonic transformation strategy: by synchronously rotating the coordinates of the fifth and seventh harmonics, the second-order harmonics are uniformly transformed into the sixth-order harmonic domain; using a Park transform with a sixth-harmonic angle, combined with an amplitude reconstruction strategy and a zero-reduction prevention strategy, the sixth-order harmonic is converted into a DC component. Based on this, a Park coordinate transformation is performed on the normalized sixth-order harmonic using a sixth-harmonic rotation angle, effectively eliminating harmonic residues after the Park transform, unlike the amplitude reconstruction and normalization process. Without normalization, the Park transform cannot effectively convert the AC component into a DC component, leading to a deterioration in the extraction accuracy of the fifth and seventh harmonics.

[0095] In some embodiments, the sixth-harmonic rotation angle transformation in step S50 employs a sixth-harmonic Park transform. The sixth-harmonic Park transform accurately converts the AC signal to a rotating coordinate system, achieving signal decoupling. This transformation method effectively extracts harmonic components of specific frequencies, providing accurate signal basis for subsequent harmonic suppression. Furthermore, this transformation process involves relatively low computational load, enabling rapid signal processing to meet the needs of real-time motor control, ensuring timely harmonic suppression during motor operation, and improving motor operational stability and performance.

[0096] The two DC quantities after transformation are passed through a PI controller and the compensation components of UX and UY are obtained through closed-loop control. The compensation is then injected into the original XY control loop, which effectively solves the defect of insufficient suppression of fifth and seventh harmonics of the original XY plane controller and constructs a global harmonic suppression and compensation system.

[0097] Figure 4 A flowchart illustrating a compensation voltage generation scheme provided for at least one embodiment of this disclosure. Figure 1 , Figure 2 or Figure 3 Based on this, in order to effectively eliminate harmonic components other than the fifth and seventh harmonics, the DC quantity includes X-direction DC quantity and Y-direction DC quantity, and, as Figure 4 As shown, step S60 is further refined into the following sub-steps S601-S602.

[0098] Sub-step S601: The X-direction DC flow is controlled in a closed loop by a preset first proportional-integral controller to generate an X-direction dynamic compensation voltage.

[0099] Sub-step S602: The Y-direction DC flow is controlled in a closed loop by a preset second proportional-integral controller to generate a Y-direction dynamic compensation voltage.

[0100] The above scheme does not require the use of filters for decoupling control. Instead, it directly generates the X-axis dynamic compensation voltage by performing closed-loop control on the extracted X-axis DC quantity through a first proportional-integral controller. The extracted Y-axis DC quantity is directly controlled in a closed loop by a second proportional-integral controller to generate a dynamic compensation voltage in the Y-axis direction. Dynamically inject the original control loop.

[0101] The above scheme reconstructs the suppression system on the harmonic XY plane, and injects the transformed DC quantity into the original control loop through PI closed-loop control. It can dynamically track and coordinate the suppression of harmonic components other than the fifth and seventh harmonics through two proportional-integral controllers (also known as PI controllers).

[0102] Figure 5A flowchart illustrating another motor harmonic suppression method provided for at least one embodiment of this disclosure. Figure 4 Based on this, in order to further ensure the harmonic suppression effect, such as Figure 5 As shown, the method further includes the following step S80.

[0103] Step S80: By adjusting the coefficients of the first proportional-integral controller and the second proportional-integral controller, independent configuration of the suppression bandwidth of different order harmonics can be achieved.

[0104] By adjusting the parameters of the first proportional-integral controller, its suppression bandwidth for specific harmonic orders can be flexibly set, ensuring that specific harmonic orders are effectively controlled during motor operation and reducing their negative impact on motor performance. Similarly, by adjusting the parameters of the second proportional-integral controller, its suppression of other harmonic orders can be independently configured, achieving personalized settings for the suppression of different harmonic orders. This further optimizes the motor's harmonic suppression effect and improves the stability and reliability of motor operation.

[0105] Figure 6 A control diagram illustrating an example of a motor harmonic suppression method provided in at least one embodiment of this disclosure. (See diagram below.) Figure 6 As shown, this scheme adds two PI controllers to the original dual Y30 dual three-phase motor VSD control strategy. Specifically, these are DQ-axis current PI controllers that convert the fifth and seventh harmonics into sixth harmonics. Through a novel coordinate transformation matrix, the fifth and seventh harmonics are converted into sixth harmonics and then into DC current. The PI controllers are then used for control, ultimately injecting the current into the original harmonic XY plane. This process eliminates the need for filters and allows for direct control via the PI controllers. and The compensation value avoids the complex filter parameter tuning process and the performance degradation problem caused by parameter issues.

[0106] Figure 7 This is a structural block diagram of a motor harmonic suppression system provided in at least one embodiment of the present disclosure. This motor harmonic suppression system is applied to multiphase motors, including but not limited to dual Y30 six-phase motors. Figure 7 As shown, the motor harmonic suppression system 10 includes a signal acquisition unit 11, a signal conversion unit 12, a harmonic processing unit 13, a harmonic suppression unit 14, and a signal injection unit 15.

[0107] The signal acquisition unit 11 is configured to acquire the multiphase current of the motor.

[0108] The signal conversion unit 12 is configured to perform space vector decoupling transformation on the multiphase current to obtain the current component of the harmonic XY plane, and to convert the 6K-1th harmonic and 6K+1th harmonic of the current component into the 6Kth harmonic, where K≥1.

[0109] The harmonic processing unit 13 is configured to normalize the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic, and to perform a six-fold frequency rotation angle transformation on the normalized current component to generate a DC component.

[0110] The harmonic suppression unit 14 is configured to generate a compensation voltage based on DC flow.

[0111] The signal injection unit 15 is configured to inject a compensation voltage into the control circuit of the motor to suppress harmonics.

[0112] The specific execution methods of each unit in the above system embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0113] In some embodiments, Figure 7 Based on this, the signal acquisition unit 11 can be implemented by a corresponding sensor, and the signal conversion unit 12, harmonic processing unit 13, and harmonic suppression unit 14 can be implemented by a controller or control module with corresponding programs.

[0114] This disclosure also provides a storage medium storing a program or instructions that, when executed by a processor, implement the steps of the method embodiments described above.

[0115] This disclosure also provides a program product, such as... Figure 8 As shown, the program product includes one or more processors 21 and memory 22. Figure 8 Take a processor 21 as an example.

[0116] The controller may also include an input device 23 and an output device 24.

[0117] The processor 21, memory 22, input device 23, and output device 24 can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0118] The processor 21 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips. The general-purpose processor can be a microprocessor or any conventional processor.

[0119] The memory 22, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 21 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions, and modules stored in the memory 22, thereby implementing the steps of the above-described method embodiments.

[0120] The memory 22 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the use of the processing device operated by the server. Furthermore, the memory 22 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 22 may optionally include memory remotely located relative to the processor 21, and these remote memories may be connected to a network connection device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0121] Input device 23 can receive input digital or character information, and generate key signal inputs related to driver settings and function control of the server's processing unit. Output device 24 may include display devices such as a display screen.

[0122] One or more modules are stored in memory 22, and when executed by one or more processors 21, they perform actions such as... Figure 1 The method shown.

[0123] Those skilled in the art will understand that all or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0124] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

[0125] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A method for suppressing harmonics in a motor, characterized in that, include: Obtain the multiphase current of the motor; The multiphase current is subjected to space vector decoupling transformation to obtain the current components of the harmonic XY plane; The 6K-1 and 6K+1 harmonics of the current component are converted into the 6K harmonic, where K is a positive integer. Based on the 6K harmonic, the 6K-1 and 6K+1 harmonics of the current component are normalized to achieve amplitude reconstruction. The normalized current component is subjected to a sixth-harmonic rotation angle transformation to generate a DC current. A compensation voltage is generated based on the DC flow rate; and... The compensation voltage is injected into the control circuit of the motor to suppress harmonics.

2. The method according to claim 1, characterized in that, The current component includes an X-axis current component and a Y-axis current component, K=1, and the step of converting the 6K-1th and 6K+1th harmonics of the current component into a 6Kth harmonic includes: The fifth harmonic is obtained based on the difference between the X-direction current component and the Y-direction current component. The seventh harmonic is obtained based on the sum of the X-direction current component and the Y-direction current component. Based on the amplitude difference between the fifth and seventh harmonics, a converted X-direction current component is generated, wherein the amplitude of the converted X-direction current component is positively correlated with the amplitude difference; and, Based on the sum of the amplitudes of the fifth and seventh harmonics, a converted Y-direction current component is generated, wherein the amplitude of the converted Y-direction current component is positively correlated with the sum of the amplitudes, and the converted X-direction current component and the converted Y-direction current component each contain different sixth harmonics.

3. The method according to claim 1 or 2, characterized in that, The normalization process for the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic includes: The converted X-direction current component is normalized based on a sine function of six times the electrical angle to generate the first coefficient; The transformed Y-direction current component is normalized using a cosine function based on six times the electrical angle to generate a second coefficient. Based on the second coefficient and the X-direction current component obtained through space vector decoupling transformation, a normalized X-direction current component is generated; and, Based on the first coefficient and the Y-direction current component obtained through space vector decoupling transformation, a normalized Y-direction current component is generated.

4. The method according to claim 3, characterized in that, The normalization process includes a zero-division protection strategy, which is configured to: when the divisor in the normalization process is zero, set the corresponding first coefficient or second coefficient to a preset value.

5. The method according to claim 3, characterized in that, The first coefficient is configured as follows: The product of the electric angular velocity of the motor and time is not equal. When the first coefficient is the ratio of the converted X-direction current component to the sine function of the six times electrical angle; as well as, The product of the electric angular velocity of the motor and time is When the first coefficient is set to zero, it is used to prevent the coefficient from being removed from zero.

6. The method according to claim 3, characterized in that, The second coefficient is configured as follows: The product of the electric angular velocity of the motor and time is not equal. When the second coefficient is the ratio of the converted Y-direction current component to the cosine function of the six times electrical angle; as well as, The product of the electric angular velocity of the motor and time is When the second coefficient is zero, it is set to zero to achieve zero-prevention protection.

7. The method according to claim 1 or 2, characterized in that, The DC flow includes X-axis DC flow and Y-axis DC flow, and the generation of compensation voltage based on the DC flow includes: The X-axis DC quantity is subjected to closed-loop control by a preset first proportional-integral controller to generate an X-axis dynamic compensation voltage; and... The Y-axis DC flow is controlled in a closed loop by a preset second proportional-integral controller to generate a Y-axis dynamic compensation voltage.

8. The method according to claim 7, characterized in that, The space vector decoupling transformation employs VSD transformation, and the sixth-harmonic rotation angle transformation employs sixth-harmonic Park transformation; furthermore, the method also includes: By adjusting the coefficients of the first proportional-integral controller and the second proportional-integral controller, independent configuration of the suppression bandwidth for different orders of harmonics can be achieved.

9. A motor harmonic suppression system, characterized in that, include: The signal acquisition unit is configured to acquire the multiphase current of the motor; The signal conversion unit is configured to perform space vector decoupling transformation on the multiphase current to obtain the current components in the harmonic XY plane, and to convert the 6K-1th and 6K+1th harmonics of the current components into a 6Kth harmonic, where K≥1; and, The harmonic processing unit is configured to normalize the 6K-1 and 6K+1 harmonics of the current component based on the 6K harmonic, and to perform a six-fold frequency rotation angle transformation on the normalized current component to generate a DC component. The harmonic suppression unit is configured to generate a compensation voltage based on the DC quantity; and, The signal injection unit is configured to inject the compensation voltage into the control circuit of the motor to suppress harmonics.

10. A storage medium, characterized in that, The storage medium stores a program or instructions, wherein the program or instructions, when executed by a processor, implement the steps of the method as described in any one of claims 1 to 8.

Images