Method and device for suppressing harmonic current of permanent magnet synchronous motor at low switching frequency

Abstract

The present disclosure proposes a method and device for suppressing harmonic current of a permanent magnet synchronous motor under low switching frequency, the method comprising: determining the predicted current data of the motor at time K+1; determining the number of switching actions of the motor inverter at time K+1 relative to time K according to the predicted current data, wherein time K is the current time; determining the target harmonic component of the motor current at time K+1 according to the predicted current data; constructing a target cost function based on the number of switching actions and the target harmonic component; determining the target voltage vector from multiple basic voltage vectors of the motor inverter based on the target cost function, and applying the target voltage vector to the motor inverter. By implementing the method disclosed in the present disclosure, the number of switching actions and the target harmonic component can be comprehensively considered in the process of determining the target voltage vector, thereby ensuring the applicability of the obtained target voltage vector, and greatly improving the steady-state control performance of the permanent magnet synchronous motor under low switching frequency.

Description

Technical Field

[0001] The present disclosure relates to the technical field of motor control, and in particular to a method and device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency. Background Art

[0002] Permanent-magnet synchronous motor (PMSM) is widely used in electric vehicles, AC servo systems and wind power generation due to its high efficiency, high power density and wide speed regulation range. Model Predictive Control (MPC), as an advanced control method, has gradually become a research hotspot in the field of PMSM drive in recent years.

[0003] Finite Control Set Model Predictive Control (FCS-MPC), also known as direct MPC with reference tracking, is the most popular method in the field of MPC. Among them, the most widely used is Model Predictive Current Control (MPCC). MPC has two most important performance indicators, namely switching frequency and total harmonic distortion (THD) of load current. Due to different application scenarios, the requirements for switching frequency are very stringent. For example, in high-power traction systems such as railways, a relatively low switching frequency is required to reduce power losses caused by switching actions.

[0004] In this way, as the switching frequency decreases, the THD of the motor current will increase, thereby affecting the steady-state control effect of the system. Summary of the invention

[0005] The present disclosure aims to solve one of the technical problems in the related art at least to some extent.

[0006] To this end, the purpose of the present disclosure is to propose a method, device, computer equipment and storage medium for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency, thereby making it possible to comprehensively consider the number of switching actions and the target harmonic component in the process of determining a target voltage vector, thereby ensuring the applicability of the obtained target voltage vector and greatly improving the steady-state control performance of the permanent magnet synchronous motor at a low switching frequency.

[0007] To achieve the above-mentioned purpose, a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency is proposed in a first aspect of the present disclosure, comprising:

[0008] Determine the predicted current data of the motor at time K+1;

[0009] Determine the number of switching actions of the motor inverter at the K+1 time relative to the K time according to the predicted current data, wherein the K time is the current time;

[0010] Determining a target harmonic component of the motor current at the time K+1 according to the predicted current data;

[0011] constructing a target cost function based on the number of switching actions and the target harmonic component;

[0012] A target voltage vector is determined from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and the target voltage vector is applied to the motor inverter.

[0013] To achieve the above-mentioned purpose, a device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency is provided in a second aspect of the present disclosure, comprising:

[0014] The first determination module is used to determine the predicted current data of the motor at time K+1;

[0015] A second determination module is used to determine the number of switching actions of the motor inverter at the K+1 moment relative to the K moment according to the predicted current data, wherein the K moment is the current moment;

[0016] A third determination module, used to determine the target harmonic component of the current of the motor at the time K+1 according to the predicted current data;

[0017] A function building module, used for building a target cost function based on the number of switching actions and the target harmonic component;

[0018] A fourth determination module is used to determine a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and apply the target voltage vector to the motor inverter.

[0019] The computer device proposed in the third aspect embodiment of the present disclosure includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in the first aspect embodiment of the present disclosure is implemented.

[0020] The fourth aspect embodiment of the present disclosure proposes a non-temporary computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency as proposed in the first aspect embodiment of the present disclosure.

[0021] The fifth aspect embodiment of the present disclosure proposes a computer program product. When the instructions in the computer program product are executed by a processor, the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in the first aspect embodiment of the present disclosure is executed.

[0022] The present disclosure provides a method, device, computer equipment and storage medium for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency, by determining the predicted current data of the motor at time K+1, and determining the number of switching actions of the motor inverter at time K+1 relative to time K according to the predicted current data, wherein time K is the current time, and determining the target harmonic component of the motor current at time K+1 according to the predicted current data, constructing a target cost function based on the number of switching actions and the target harmonic component, determining the target voltage vector from multiple basic voltage vectors of the motor inverter based on the target cost function, and applying the target voltage vector to the motor inverter. Thus, the number of switching actions and the target harmonic component can be comprehensively considered in the process of determining the target voltage vector, thereby ensuring the applicability of the obtained target voltage vector, and greatly improving the steady-state control performance of the permanent magnet synchronous motor at a low switching frequency.

[0023] Additional aspects and advantages of the present disclosure will be given in part in the following description and in part will be obvious from the following description or learned through practice of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present disclosure will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0025] Figure 1 It is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in an embodiment of the present disclosure;

[0026] Figure 2 is a schematic diagram of the distribution of multiple basic voltage vectors proposed in the present disclosure;

[0027] Figure 3 is a schematic diagram of the structure of a two-level voltage source inverter;

[0028] Figure 4 is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in another embodiment of the present disclosure;

[0029] Figure 5 This is the block diagram of the traditional single vector model predictive current control;

[0030] Figure 6 is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in another embodiment of the present disclosure;

[0031] Figure 7 is a block diagram of a single vector model predictive current control proposed in the present disclosure;

[0032] Figure 8a It is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 500r / min;

[0033] Figure 8b It is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 1000r / min;

[0034] Figure 8c It is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 1500r / min;

[0035] Figure 8d It is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 2000r / min;

[0036] Figure 9a It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 500r / min;

[0037] Figure 9b It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 1000r / min;

[0038] Fig.9c It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 1500r / min;

[0039] Figure 9d It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 2000r / min;

[0040] Fig.10 is a schematic diagram of the values ​​of the switching frequency, the switching frequency limiting factor and the harmonic limiting factor proposed in the present disclosure;

[0041] Fig.11 It is a schematic diagram comparing the d-axis current ripple size of the MPCC method at low switching frequency and the method provided in the embodiment of the present application within the full speed range;

[0042] Fig.12 It is a schematic diagram comparing the q-axis current ripple size in the full speed range of the MPCC method at a low switching frequency and the method provided in the embodiment of the present application;

[0043] Fig.13It is a schematic diagram of the structure of a device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in an embodiment of the present disclosure;

[0044] Fig.14 A block diagram of an exemplary computer device suitable for implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0045] Embodiments of the present disclosure are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present disclosure, and are not to be construed as limitations of the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications, and equivalents that fall within the spirit and connotation of the appended claims.

[0046] Figure 1 It is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in an embodiment of the present disclosure.

[0047] Among them, it should be noted that the executor of the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency in this embodiment is a device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency. The device can be implemented by software and / or hardware. The device can be configured in a computer device. The computer device can include but is not limited to a terminal, a server, etc. For example, the terminal can be a mobile phone, a handheld computer, etc.

[0048] like Figure 1 As shown, the method for suppressing harmonic current of the permanent magnet synchronous motor at low switching frequency includes:

[0049] S101: Determine the predicted current data of the motor at time K+1.

[0050] The motor may refer to a permanent magnet synchronous motor for which harmonic current suppression is to be performed in the embodiments of the present disclosure.

[0051] Here, the K+1 moment may refer to the next moment relative to the current moment.

[0052] Among them, the predicted current data can be used to describe the current situation of the motor at time K+1.

[0053] In the disclosed embodiment, when determining the predicted current data of the motor at time K+1, it can be based on a third-party current prediction device, or it can also be based on mathematical or engineering methods to determine the predicted current data of the motor at time K+1, and there is no limitation on this.

[0054] In the embodiment of the present disclosure, when the predicted current data of the motor at time K+1 is determined, reliable data support can be provided for the subsequent determination of the number of switching actions and the target harmonic component.

[0055] S102: Determine the number of switching actions of the motor inverter at time K+1 relative to time K based on the predicted current data, where time K is the current time.

[0056] The number of switching actions refers to the number of switching actions of the switching device of the motor inverter between the adjacent K+1 moment and K moment.

[0057] In the embodiment of the present disclosure, when determining the number of switching actions of the motor inverter at time K+1 relative to time K based on the predicted current data, it can be based on a preconfigured relationship table, or it can also be based on a method combining numbers and shapes to determine the number of switching actions of the motor inverter at time K+1 relative to time K based on the predicted current data, and there is no limitation on this.

[0058] In the disclosed embodiment, when the number of switching actions of the motor inverter at time K+1 relative to time K is determined based on the predicted current data, data support for the number of switching actions dimension can be provided for the subsequent construction of the target cost function.

[0059] S103: Determine the target harmonic component of the motor current at time K+1 according to the predicted current data.

[0060] The target harmonic component may refer to the harmonic component of the motor current at time K+1.

[0061] In the embodiments of the present disclosure, when determining the target harmonic component of the motor current at time K+1 based on the predicted current data, the predicted current data can be processed based on a pre-trained machine learning model to obtain the target harmonic component, or any other possible method can be used to determine the target harmonic component of the motor current at time K+1 based on the predicted current data, without limitation.

[0062] In the embodiment of the present disclosure, when the target harmonic component of the motor current at time K+1 is determined based on the predicted current data, data support of the harmonic component dimension can be provided for the subsequent construction of the target cost function.

[0063] S104: Constructing a target cost function based on the number of switching actions and the target harmonic component.

[0064] The target cost function refers to a cost function constructed based on the number of switching actions and the target harmonic component in the embodiment of the present disclosure, which can be used to evaluate various possible control schemes.

[0065] In the embodiment of the present disclosure, when a target cost function is constructed based on the number of switching actions and the target harmonic component, the obtained target cost function can be effectively integrated with relevant information of the number of switching actions and the target harmonic component.

[0066] S105: Determine a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and apply the target voltage vector to the motor inverter.

[0067] For example, Figure 2 As shown, Figure 2 is a schematic diagram of the distribution of multiple basic voltage vectors proposed according to the present disclosure.

[0068] The target voltage vector may refer to a voltage vector with optimal performance determined from a plurality of basic voltage vectors of the motor inverter based on a target cost function.

[0069] That is to say, in the embodiment of the present disclosure, after constructing the target cost function based on the number of switching actions and the target harmonic component, the target voltage vector can be determined from multiple basic voltage vectors of the motor inverter based on the target cost function, and the target voltage vector can be applied to the motor inverter, thereby achieving comprehensive consideration of the number of switching actions and the target harmonic component, and ensuring the applicability of the obtained target voltage vector.

[0070] In this embodiment, by determining the predicted current data of the motor at time K+1, the number of switching actions of the motor inverter at time K+1 relative to time K is determined based on the predicted current data, wherein time K is the current time, and the target harmonic component of the motor current at time K+1 is determined based on the predicted current data, a target cost function is constructed based on the number of switching actions and the target harmonic component, a target voltage vector is determined from multiple basic voltage vectors of the motor inverter based on the target cost function, and the target voltage vector is applied to the motor inverter. Thus, the number of switching actions and the target harmonic component can be comprehensively considered in the process of determining the target voltage vector, thereby ensuring the applicability of the obtained target voltage vector, and greatly improving the steady-state control performance of the permanent magnet synchronous motor at low switching frequency.

[0071] In one embodiment provided in the present application, the permanent magnet synchronous motor adopts a surface mounted permanent magnet synchronous motor (SPMSM) drive system of a two-level inverter, including a d-axis and a q-axis, such as Figure 3 As shown, Figure 3 It is a schematic diagram of the structure of a two-level voltage source inverter. The two-level voltage source inverter can output eight voltage vectors according to different switching states. The switching states corresponding to these eight voltage vectors can be expressed as S∈N 0～7={000, 100, 110, 010, 011, 001, 101, 111}. Among them, S1 to S6 are transistors, and D1 to D6 are diodes. Since the inductance of the d-axis and q-axis of the surface-mounted permanent magnet synchronous motor is equal, that is, L d =L q =L, therefore, the voltage equation of the permanent magnet synchronous motor in the embodiment of the present application can be expressed as:

[0072]

[0073] Among them, u d ,u q is the d, q axis stator voltage component, R is the resistance parameter, i d ,i q are the currents on the d-axis and q-axis respectively, L is the inductance parameter, t is the time, ω e is the electrical angular velocity of the motor, ψ f is the initial flux parameter.

[0074] Figure 4 It is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in another embodiment of the present disclosure.

[0075] like Figure 4 As shown, the method for suppressing harmonic current of the permanent magnet synchronous motor at low switching frequency includes:

[0076] S401: Acquire initial current data of the motor at time K, wherein the initial current data includes: a d-axis current sampling value and a q-axis current sampling value.

[0077] The d-axis current sampling value and the q-axis current sampling value refer to current values ​​obtained by sampling the d-axis current and the q-axis current of the motor at time K.

[0078] It can be understood that, in the embodiment of the present disclosure, after the initial current data of the motor at time K is obtained, reliable reference information can be provided for the subsequent prediction of the d-axis current prediction value and the q-axis current prediction value.

[0079] S402: Processing the d-axis current sampling value and the q-axis current sampling value based on a preset current prediction model to obtain a d-axis current prediction value and a q-axis current prediction value.

[0080] The current prediction model may refer to a pre-acquired current prediction model in a traditional single vector model predictive current control (MPCC).

[0081] For example, Figure 5 As shown, Figure 5This is the traditional single vector model prediction current control block diagram, which includes two parts: prediction and optimization. The corresponding control system block diagram is represented as: current prediction model and cost function. The current prediction model expression is:

[0082]

[0083] Among them, k is the current time, are the current prediction values ​​at time k+1 on the d-axis and q-axis respectively, T is the control period, R is the resistance parameter, L is the inductance parameter, ψ f is the flux linkage parameter, i d (k), i q (k) are the current sampling values ​​at time k on the d-axis and q-axis respectively, ω e is the electrical angular velocity of the motor, u d (k) and u q (k) are the voltages of the optimal voltage vector on the d-axis and q-axis at time k respectively.

[0084] The d-axis current prediction value and the q-axis current prediction value may refer to predicted current values ​​at time K+1 obtained based on sampling processing of the d-axis current sampling value and the q-axis current sampling value, respectively.

[0085] That is to say, in the embodiment of the present disclosure, the initial current data of the motor at time K can be obtained, wherein the initial current data includes: a d-axis current sampling value and a q-axis current sampling value, and the d-axis current sampling value and the q-axis current sampling value are processed based on a preset current prediction model to obtain a d-axis current prediction value and a q-axis current prediction value, thereby quickly realizing accurate prediction of the d-axis current value and the q-axis current value at time K+1 based on the d-axis current sampling value and the q-axis current sampling value.

[0086] S403: Determine the initial switching state of the motor inverter at time K.

[0087] The initial switching state can be used to describe the switching status of the internal switching device of the motor inverter at time K.

[0088] S404: Determine the predicted switching state of the motor inverter at time K+1 according to the d-axis current predicted value and the q-axis current predicted value.

[0089] The predicted switching state may refer to the predicted switching state of the motor inverter at time K+1.

[0090] That is, in the embodiment of the present disclosure, the switching state of the motor inverter can be reversed according to the d-axis current prediction value and the q-axis current prediction value to obtain the switching state of the motor inverter at time K+1.

[0091] S405: Based on the initial switch state and the predicted switch state, the number of switch actions is calculated and determined.

[0092] For example, in the embodiment of the present disclosure, the inverter switching state at the current moment can be represented as S according to the prediction result at the previous moment. abc (k). The inverter switch state at the next moment can be expressed as S abc (k+1). Therefore, the number of switching actions n of the inverter from the kth moment to the k+1th moment can be expressed as follows:

[0093]

[0094] Among them, S abc (k) and S abc (k+1) all belong to N 0～7 .

[0095] That is to say, in the embodiment of the present disclosure, after obtaining the d-axis current prediction value and the q-axis current prediction value, the initial switching state of the motor inverter at time K can be determined, and the predicted switching state of the motor inverter at time K+1 can be determined based on the d-axis current prediction value and the q-axis current prediction value. Based on the initial switching state and the predicted switching state, the number of switching actions is calculated and determined. Thus, the number of switching actions can be accurately and quickly determined in combination with the initial switching state and the predicted switching state.

[0096] S406: Determine the target fundamental wave component of the motor at time K+1, wherein the target fundamental wave component includes: a d-axis target fundamental wave component and a q-axis target fundamental wave component.

[0097] Optionally, in some embodiments, when determining the target fundamental component of the motor at time K+1, the initial fundamental component of the motor at time K can be obtained, wherein the initial fundamental component includes: a d-axis initial fundamental component and a q-axis initial fundamental component, and the d-axis current prediction value and the d-axis initial fundamental component are processed based on a preset low-pass filter to obtain the d-axis target fundamental component, and the q-axis current prediction value and the q-axis initial fundamental component are processed based on a low-pass filter to obtain the q-axis target fundamental component. Thus, the accuracy and reliability of the obtained d-axis target fundamental component and q-axis target fundamental component can be guaranteed.

[0098] S407: Calculate the difference between the d-axis current prediction value and the d-axis target fundamental component as the d-axis target harmonic component.

[0099] S408: Calculate the difference between the q-axis current prediction value and the q-axis target fundamental component as the q-axis target harmonic component, wherein the d-axis target harmonic component and the q-axis target harmonic component jointly constitute the target harmonic component.

[0100] That is to say, in the embodiment of the present disclosure, the target fundamental component of the motor at time K+1 can be determined, wherein the target fundamental component includes: a d-axis target fundamental component and a q-axis target fundamental component, and the difference between the d-axis current prediction value and the d-axis target fundamental component is calculated as the d-axis target harmonic component, and the difference between the q-axis current prediction value and the q-axis target fundamental component is calculated as the q-axis target harmonic component, wherein the d-axis target harmonic component and the q-axis target harmonic component jointly constitute the target harmonic component, thereby effectively improving the reliability of the target harmonic component determination process.

[0101] For example, in the embodiment of the present disclosure, a current harmonic separation controller can be constructed to obtain the target harmonic component. The expression of the current harmonic separation controller includes:

[0102]

[0103] in Respectively represent the fundamental component expressions of the predicted current at time k+1 on the d-axis and q-axis. They represent the expressions of the fundamental components of the predicted current at time k on the d-axis and q-axis respectively. They are the predicted current values ​​at time k+1 on the d-axis and q-axis respectively.

[0104] Therefore, the harmonic currents of the predicted current are as follows:

[0105]

[0106] in They represent the harmonic component expressions of the predicted current at time k+1 on the d-axis and q-axis respectively.

[0107] S409: Constructing a target cost function based on the number of switching actions and the target harmonic component.

[0108] S410: Determine a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on a target cost function, and apply the target voltage vector to the motor inverter.

[0109] The description of S409 and S410 can be specifically referred to the above embodiment, which will not be repeated here.

[0110] In this embodiment, by obtaining the initial current data of the motor at time K, wherein the initial current data includes: a d-axis current sampling value and a q-axis current sampling value, the d-axis current sampling value and the q-axis current sampling value are processed based on a preset current prediction model to obtain a d-axis current prediction value and a q-axis current prediction value, thereby, based on the d-axis current sampling value and the q-axis current sampling value, an accurate prediction of the d-axis current value and the q-axis current value at time K+1 can be quickly achieved. The initial switching state of the motor inverter at time K is determined, and the predicted switching state of the motor inverter at time K+1 is determined according to the d-axis current prediction value and the q-axis current prediction value. Based on the initial switching state and the predicted switching state, the number of switching actions is calculated and determined, thereby, the number of switching actions can be accurately and quickly determined in combination with the initial switching state and the predicted switching state. Determine the target fundamental component of the motor at time K+1, wherein the target fundamental component includes: a d-axis target fundamental component and a q-axis target fundamental component, calculate the difference between the d-axis current prediction value and the d-axis target fundamental component as the d-axis target harmonic component, calculate the difference between the q-axis current prediction value and the q-axis target fundamental component as the q-axis target harmonic component, wherein the d-axis target harmonic component and the q-axis target harmonic component jointly constitute the target harmonic component, thereby effectively improving the reliability of the target harmonic component determination process.

[0111] Figure 6 It is a flow chart of a method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in another embodiment of the present disclosure.

[0112] like Figure 6 As shown, the method for suppressing harmonic current of the permanent magnet synchronous motor at low switching frequency includes:

[0113] S601: Acquire initial current data of the motor at time K, wherein the initial current data includes: a d-axis current sampling value and a q-axis current sampling value.

[0114] S602: Processing the d-axis current sampling value and the q-axis current sampling value based on a preset current prediction model to obtain a d-axis current prediction value and a q-axis current prediction value, wherein the d-axis current prediction value and the q-axis current prediction value jointly constitute predicted current data.

[0115] S603: Determine the number of switching actions of the motor inverter at time K+1 relative to time K based on the predicted current data, where time K is the current time.

[0116] S604: Determine the target harmonic component of the motor current at time K+1 according to the predicted current data.

[0117] The description of S601 - S604 can be specifically referred to the above embodiment, which will not be repeated here.

[0118] S605: Obtain a d-axis current reference value and a q-axis current reference value of the motor.

[0119] The d-axis current reference value and the q-axis current reference value may be determined by an application scenario, and there is no restriction on this.

[0120] S606: constructing an initial cost function according to the d-axis current prediction value, the q-axis current prediction value, the d-axis current reference value and the q-axis current reference value.

[0121] For example, the initial cost function can be expressed as:

[0122]

[0123] S607: Determine a switching frequency limiting factor corresponding to the number of switching actions, wherein the switching frequency limiting factor is used to balance the order of magnitude relationship between the predicted current and the number of inverter actions.

[0124] It is understandable that the predicted current and the number of inverter actions may be of different orders of magnitude, so the two cannot be directly combined for calculation. Therefore, when determining the switching frequency limit factor corresponding to the number of switching actions, it can provide reliable reference information for subsequently substituting the number of switching actions into the initial cost function.

[0125] S608: Determine a harmonic suppression factor corresponding to the target harmonic component, wherein the harmonic suppression factor is used to balance the order of magnitude relationship between the predicted current and the predicted current harmonics.

[0126] It is understandable that the predicted current and the predicted current harmonics may also be of different orders of magnitude, so a harmonic suppression factor corresponding to the target harmonic component can be determined to balance the order of magnitude relationship between the predicted current and the predicted current harmonics in the subsequent process of constructing the target cost function.

[0127] S609: adjusting the initial cost function according to the number of switching actions, the switching frequency limiting factor, the target harmonic component and the harmonic suppression factor to obtain a target cost function.

[0128] In the embodiment of the present disclosure, in order to limit the switching frequency of the system, the number n of inverter switching actions is introduced into formula (6), so that formula (6) can be rewritten as formula (7), as shown below:

[0129]

[0130] in, They are represented as given currents of the d-axis and q-axis respectively. λ1 is the switching frequency limiting factor, and λ1 can be adjusted according to the switching frequency requirements.

[0131] In order to improve the steady-state control performance of the motor at low switching frequency, the advantage of using the current harmonic separator method is that the separator has a simple structure and can obtain the harmonic components of the predicted current without complex calculations, and can improve the steady-state control performance of the system by limiting the harmonic components.

[0132] In order to limit the current harmonics of the system, it will be introduced in formula (7) so that formula (7) can be rewritten as formula (8) as follows:

[0133]

[0134] Where term1 is the current harmonic suppression term. term2 is the switching frequency limit term. H1 is the harmonic suppression factor. λ2 is the switching frequency limit factor.

[0135] That is to say, in the embodiment of the present disclosure, after obtaining the d-axis current prediction value, the q-axis current prediction value, the number of switching actions and the target harmonic component, the d-axis current reference value and the q-axis current reference value of the motor can be obtained, and the initial cost function can be constructed according to the d-axis current prediction value, the q-axis current prediction value, the d-axis current reference value and the q-axis current reference value, and the switching frequency limiting factor corresponding to the number of switching actions is determined, wherein the switching frequency limiting factor is used to balance the order of magnitude relationship between the predicted current and the number of inverter actions, and the harmonic suppression factor corresponding to the target harmonic component is determined, wherein the harmonic suppression factor is used to balance the order of magnitude relationship between the predicted current and the predicted current harmonics, and the initial cost function is adjusted according to the number of switching actions, the switching frequency limiting factor, the target harmonic component and the harmonic suppression factor to obtain the target cost function. In this way, the indication effect of the obtained target cost function can be effectively improved.

[0136] S610: Inputting a basic voltage vector into a preset current prediction model to obtain a current prediction value corresponding to the basic voltage vector.

[0137] S611: Substitute the current prediction value into the target cost function to obtain a cost function calculation value corresponding to the current prediction value.

[0138] S612: Determine a minimum value among the multiple cost function calculation values, and use a basic voltage vector corresponding to the minimum value as a target voltage vector.

[0139] That is, in the embodiment of the present disclosure, after obtaining the target cost function, the basic voltage vector can be input into the preset current prediction model to obtain the current prediction value corresponding to the basic voltage vector, the current prediction value is substituted into the target cost function to obtain the cost function calculation value corresponding to the current prediction value, the minimum value among the multiple cost function calculation values ​​is determined, and the basic voltage vector corresponding to the minimum value is used as the target voltage vector. Thus, the optimal target voltage vector can be accurately and quickly determined from multiple basic voltage vectors by combining the current prediction model and the target cost function.

[0140] In this embodiment, by obtaining the d-axis current reference value and the q-axis current reference value of the motor, an initial cost function is constructed according to the d-axis current prediction value, the q-axis current prediction value, the d-axis current reference value and the q-axis current reference value, and the switching frequency limiting factor corresponding to the number of switching actions is determined, wherein the switching frequency limiting factor is used to balance the order of magnitude relationship between the predicted current and the number of inverter actions, and the harmonic suppression factor corresponding to the target harmonic component is determined, wherein the harmonic suppression factor is used to balance the order of magnitude relationship between the predicted current and the predicted current harmonic, and the initial cost function is adjusted according to the number of switching actions, the switching frequency limiting factor, the target harmonic component and the harmonic suppression factor to obtain the target cost function. Thus, the indication effect of the obtained target cost function can be effectively improved. By inputting the basic voltage vector into the preset current prediction model to obtain the current prediction value corresponding to the basic voltage vector, the current prediction value is substituted into the target cost function to obtain the cost function calculation value corresponding to the current prediction value, the minimum value among the multiple cost function calculation values ​​is determined, and the basic voltage vector corresponding to the minimum value is used as the target voltage vector. Therefore, the optimal target voltage vector can be determined accurately and quickly from multiple basic voltage vectors by combining the current prediction model and the target cost function.

[0141] Based on the above embodiments, Figure 7 As shown, Figure 7 is a block diagram of the single vector model predictive current control proposed in the present disclosure. Compared with the above Figure 5 The traditional single-vector MPCC block diagram shown in the figure, the embodiment of the present application adds switching frequency limitation and current harmonic separator.

[0142] The embodiments of the present application can be verified based on an experimental platform. The parameters of the experimental platform are shown in Table 1. The rated speed of the experimental motor is 2000 r / min, the rated load torque is 5 N·m, and the control frequency set in the experiment is 15 kHz.

[0143] Table 1

[0144] parameter Parameter Definition Numeric <![CDATA[U dc (V)]]> DC bus voltage 310 <![CDATA[n N (rpm)]]> Rated speed 2000 P Pole pairs 2 R(Ω) Stator resistance 3.18 L(mH) Stator inductance 0.0085 <![CDATA[ψ f (Wb)]]> Rotor flux 0.325 <![CDATA[T e (N·m)]]> Rated torque 5

[0145] The experimental results of the MPCC method at low switching frequency are shown in Figures 8a to 8d As shown, Figure 8a This is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 500r / min. Figure 8b This is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 1000r / min. Figure 8c This is a schematic diagram of the experimental results of the MPCC method at a low switching frequency when the experimental motor speed is 1500r / min. Figure 8d The figure is a schematic diagram of the experimental results of the MPCC method under low switching frequency when the experimental motor speed is 2000r / min. The steady-state control effect was tested when the speed is 500r / min, 1000r / min, 1500r / min and 2000r / min, and the switching frequency is 0.95kHz. The experimental results of the method provided in the embodiment of the present application are as follows: Figures 9a to 9d As shown, Figure 9a It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 500r / min. Figure 9b It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 1000r / min. Fig.9c It is a schematic diagram of the experimental results of using the method provided in the embodiment of the present application when the experimental motor speed is 1500r / min. Figure 9d It is a schematic diagram of the experimental results of the method provided in the embodiment of the present application when the experimental motor speed is 2000r / min. Experiments were conducted on the steady-state control effect when the speeds are 500r / min, 1000r / min, 1500r / min and 2000r / min and the switching frequency is 0.95kHz.

[0146] It can be seen from the experimental results that the THD of both methods increases with the increase of speed. In addition, the THD of the MPCC method at low switching frequency in the full speed range is higher than that of the method provided in the embodiment of the present application, and the THD of the method provided in the embodiment of the present application decreases more significantly at medium speed. At 1000r / min, the THD of the MPCC method at low switching frequency is 24.23%, while the THD of the method provided in the embodiment of the present application is 21.27%. At 1500r / min, the THD of the MPCC method at low switching frequency is 25.23%, while the THD of the method provided in the embodiment of the present application is 23.16%. Therefore, it can be seen from the above experimental results that during the operation of the system, the implementation method of the present application can improve the steady-state control effect of the system under low switching frequency conditions.

[0147] The MPCC method at low switching frequency and the method provided in the embodiment of the present application have the following values ​​for the switching frequency, switching frequency limiting factors λ1, λ2 and harmonic limiting factor H1 in the full speed range: Fig.10 As shown, Fig.10 This is a schematic diagram of the values ​​of the switching frequency, switching frequency limiting factor and harmonic limiting factor proposed in the present disclosure. By adjusting λ1, λ2 and H1, the switching frequencies of the MPCC method at low switching frequency and the method provided in the embodiment of the present application are both limited to 0.95kHz.

[0148] like Fig.11 and Fig.12 As shown, Fig.11 : is a schematic diagram comparing the d-axis current ripple size of the MPCC method at low switching frequency and the method provided in the embodiment of the present application in the full speed range, Fig.12 It is a schematic diagram comparing the q-axis current ripple size of the MPCC method at low switching frequency and the method provided in the embodiment of the present application in the full speed range. At 1000r / min, the d-axis current ripple of the MPCC method at low switching frequency is 4A, and the q-axis current ripple is 3.5A; the d-axis current ripple of the method provided in the embodiment of the present application is 3.8A, and the q-axis current ripple is 3.2A. In comparison, the d-axis current ripple of the method provided in the embodiment of the present application is reduced by 0.5A, and the q-axis current ripple is reduced by 0.6A. At 2000r / min, the d-axis current ripple of the MPCC method at low switching frequency is 3.5A, and the q-axis current ripple is 3.0A, while the d-axis current ripple of the method provided in the embodiment of the present application is 3.4A, and the q-axis current ripple is 2.9A. In contrast, the d-axis current ripple of the method provided in the embodiment of the present application has decreased by 0.1A, and the q-axis current ripple has decreased by 0.1A. The MPCC method at low switching frequency has a d-axis ripple of 3.8A and a q-axis ripple of 3.2A.

[0149] It can be seen from the collated experimental data that the method proposed in this application can reduce the increase in THD caused by the decrease in switching frequency, and optimize the control performance of the permanent magnet synchronous motor at low switching frequency.

[0150] The method for suppressing current harmonics of a permanent magnet synchronous motor at a low switching frequency provided in this embodiment obtains the number of switching actions of the inverter by obtaining the switching states of the inverter at two adjacent moments; in addition, the harmonic components of the predicted current are obtained by inputting the predicted current obtained by the initial prediction model into a current harmonic separator; at the same time, the obtained number of inverter switching actions is used as a switching frequency limitation item, and the obtained harmonic components of the predicted current are used as current harmonic suppression items, which are added to the cost function to limit the increase in current harmonics caused by the decrease in switching frequency; the prediction model is used to select the optimal voltage vector, and the optimal voltage vector is applied to the inverter of the permanent magnet synchronous motor, thereby optimizing the control performance of the permanent magnet synchronous motor at a low switching frequency.

[0151] Fig.13 It is a structural schematic diagram of a device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in an embodiment of the present disclosure.

[0152] like Fig.13 As shown, the device 13 for suppressing harmonic current of the permanent magnet synchronous motor at low switching frequency includes:

[0153] The first determination module 1301 is used to determine the predicted current data of the motor at time K+1;

[0154] A second determination module 1302 is used to determine the number of switching actions of the motor inverter at time K+1 relative to time K according to the predicted current data, wherein time K is the current time;

[0155] The third determination module 1303 is used to determine the target harmonic component of the motor current at time K+1 according to the predicted current data;

[0156] A function construction module 1304, for constructing a target cost function based on the number of switching actions and the target harmonic component;

[0157] The fourth determination module 1305 is used to determine a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and apply the target voltage vector to the motor inverter.

[0158] It should be noted that the aforementioned explanation of the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency is also applicable to the device for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency of this embodiment, and will not be repeated here.

[0159] In this embodiment, by determining the predicted current data of the motor at time K+1, the number of switching actions of the motor inverter at time K+1 relative to time K is determined based on the predicted current data, wherein time K is the current time, and the target harmonic component of the motor current at time K+1 is determined based on the predicted current data, a target cost function is constructed based on the number of switching actions and the target harmonic component, a target voltage vector is determined from multiple basic voltage vectors of the motor inverter based on the target cost function, and the target voltage vector is applied to the motor inverter. Thus, the number of switching actions and the target harmonic component can be comprehensively considered in the process of determining the target voltage vector, thereby ensuring the applicability of the obtained target voltage vector, and greatly improving the steady-state control performance of the permanent magnet synchronous motor at low switching frequency.

[0160] Fig.14 A block diagram of an exemplary computer device suitable for implementing embodiments of the present disclosure is shown. Fig.14 The computer device 12 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0161] like Fig.14 As shown, the computer device 12 is in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, a system memory 28, and a bus 18 that connects various system components (including the system memory 28 and the processing unit 16).

[0162] The bus 18 represents one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor or a local bus using any of a variety of bus structures. For example, these architectures include but are not limited to Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MAC) bus, Enhanced ISA bus, Video Electronics Standards Association (VESA) local bus and Peripheral Component Interconnection (PCI) bus.

[0163] The computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by the computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0164] The memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. The computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, the storage system 34 may be used to read and write non-removable, non-volatile magnetic media ( Fig.14 Not shown, often called a "hard drive").

[0165] although Fig.14 Not shown in the figure, a disk drive for reading and writing a removable non-volatile disk (e.g., a "floppy disk"), and an optical disk drive for reading and writing a removable non-volatile optical disk (e.g., a compact disc read only memory (hereinafter referred to as: CD-ROM), a digital versatile disc read only memory (hereinafter referred to as: DVD-ROM) or other optical media) may be provided. In these cases, each drive may be connected to the bus 18 via one or more data medium interfaces. The memory 28 may include at least one program product having a set (e.g., at least one) of program modules that are configured to perform the functions of the various embodiments of the present disclosure.

[0166] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in the memory 28, such program modules 42 including but not limited to an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment. The program modules 42 generally perform the functions and / or methods of the embodiments described in the present disclosure.

[0167] The computer device 12 may also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), one or more devices that enable a human body to interact with the computer device 12, and / or any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). Such communication may be performed through an input / output (I / O) interface 22. Furthermore, the computer device 12 may also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 20. Fig.14As shown, the network adapter 20 communicates with other modules of the computer device 12 via the bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems, etc.

[0168] The processing unit 16 executes various functional applications and data processing by running the programs stored in the system memory 28, such as implementing the method for suppressing harmonic current of the permanent magnet synchronous motor at low switching frequency mentioned in the above embodiment.

[0169] In order to implement the above embodiments, the present disclosure also proposes a non-temporary computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, it implements the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency as proposed in the above embodiments of the present disclosure.

[0170] In order to implement the above embodiments, the present disclosure further proposes a computer program product. When the instruction processor in the computer program product is executed, the method for suppressing harmonic current of a permanent magnet synchronous motor at a low switching frequency proposed in the above embodiments of the present disclosure is executed.

[0171] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0172] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

[0173] It should be noted that, in the description of the present disclosure, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" is two or more.

[0174] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present disclosure includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present disclosure belong.

[0175] It should be understood that the various parts of the present disclosure can be implemented in hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0176] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0177] In addition, each functional unit in each embodiment of the present disclosure may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0178] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0179] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0180] Although the embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. A method for suppressing harmonic current of a permanent magnet synchronous motor at low switching frequency, characterized in that: include: Determine predicted current data of the motor at time K+1, wherein the predicted current data includes: a d-axis current predicted value and a q-axis current predicted value; Determine the number of switching actions of the motor inverter at the K+1 time relative to the K time according to the predicted current data, wherein the K time is the current time; Determining a target harmonic component of the motor current at the time K+1 according to the predicted current data; constructing a target cost function based on the number of switching actions and the target harmonic component; determining a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and applying the target voltage vector to the motor inverter; Wherein, determining the target harmonic component of the current of the motor at the time K+1 includes: Determine the target fundamental wave component of the motor at the K+1 time, wherein the target fundamental wave component includes: a d-axis target fundamental wave component and a q-axis target fundamental wave component; Calculating a difference between the d-axis current prediction value and the d-axis target fundamental component as a d-axis target harmonic component; Calculating a difference between the q-axis current prediction value and the q-axis target fundamental component as a q-axis target harmonic component, wherein the d-axis target harmonic component and the q-axis target harmonic component jointly constitute the target harmonic component; Determining the target fundamental wave component of the motor at the K+1 time includes: Acquire the initial fundamental wave component of the motor at the time K, wherein the initial fundamental wave component includes: a d-axis initial fundamental wave component and a q-axis initial fundamental wave component; Processing the d-axis current prediction value and the d-axis initial fundamental component based on a preset low-pass filter to obtain the d-axis target fundamental component; Processing the q-axis current prediction value and the q-axis initial fundamental component based on the low-pass filter to obtain the q-axis target fundamental component; A current harmonic separation controller is constructed to obtain the target harmonic component, where the current harmonic separation controller expression includes: in, They represent the fundamental component expressions of the predicted current at time k+1 on the d-axis and q-axis respectively, They represent the fundamental component expressions of the predicted current at time k on the d-axis and q-axis respectively, are the predicted current values ​​at time k+1 on the d-axis and q-axis respectively; The d-axis target harmonic component and the q-axis target harmonic component are expressed as: in, Respectively represent the harmonic component expressions of the predicted current at time k+1 on the d-axis and q-axis; The target cost function is expressed as: Among them, term1 is the current harmonic suppression term, term2 is the switching frequency limit term, H1 is the harmonic suppression factor, λ2 is the switching frequency limit factor, They are represented as given currents of the d-axis and q-axis respectively, and n is the number of switching actions of the motor inverter at the K+1 moment relative to the K moment.

2. The method according to claim 1, characterized in that The step of determining the predicted current data of the motor at time K+1 includes: Acquire initial current data of the motor at the time K, wherein the initial current data includes: a d-axis current sampling value and a q-axis current sampling value; The d-axis current sampling value and the q-axis current sampling value are processed based on a preset current prediction model to obtain the d-axis current prediction value and the q-axis current prediction value.

3. The method according to claim 2, characterized in that Determining the number of switching actions of the motor inverter at the K+1 moment relative to the K moment according to the predicted current data includes: Determining the initial switching state of the motor inverter at the time K; Determining a predicted switching state of the motor inverter at the K+1 time according to the d-axis current predicted value and the q-axis current predicted value; The number of switch actions is determined by calculation based on the initial switch state and the predicted switch state.

4. The method according to claim 2, characterized in that The constructing a target cost function based on the number of switching actions and the target harmonic component comprises: Obtaining a d-axis current reference value and a q-axis current reference value of the motor; constructing an initial cost function according to the d-axis current prediction value, the q-axis current prediction value, the d-axis current reference value, and the q-axis current reference value; Determining a switching frequency limiting factor corresponding to the number of switching actions, wherein the switching frequency limiting factor is used to balance the order of magnitude relationship between the predicted current and the number of inverter actions; Determining a harmonic suppression factor corresponding to the target harmonic component, wherein the harmonic suppression factor is used to balance the magnitude relationship between the predicted current and the predicted current harmonics; The initial cost function is adjusted according to the number of switching actions, the switching frequency limiting factor, the target harmonic component, and the harmonic suppression factor to obtain the target cost function.

5. The method according to claim 1, characterized in that The determining a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function comprises: Inputting the basic voltage vector into a preset current prediction model to obtain a current prediction value corresponding to the basic voltage vector; Substituting the current prediction value into the target cost function to obtain a cost function calculation value corresponding to the current prediction value; A minimum value among the plurality of cost function calculation values ​​is determined, and the basic voltage vector corresponding to the minimum value is used as the target voltage vector.

6. A device for suppressing harmonic current of a permanent magnet synchronous motor at low switching frequency, characterized in that: include: A first determination module is used to determine the predicted current data of the motor at time K+1, wherein the predicted current data includes: a d-axis current predicted value and a q-axis current predicted value; A second determination module is used to determine the number of switching actions of the motor inverter at the K+1 moment relative to the K moment according to the predicted current data, wherein the K moment is the current moment; A third determination module, used to determine the target harmonic component of the current of the motor at the time K+1 according to the predicted current data; A function building module, used for building a target cost function based on the number of switching actions and the target harmonic component; a fourth determination module, configured to determine a target voltage vector from a plurality of basic voltage vectors of the motor inverter based on the target cost function, and apply the target voltage vector to the motor inverter; Wherein, determining the target harmonic component of the current of the motor at the time K+1 includes: Determine the target fundamental wave component of the motor at the K+1 time, wherein the target fundamental wave component includes: a d-axis target fundamental wave component and a q-axis target fundamental wave component; Calculating a difference between the d-axis current prediction value and the d-axis target fundamental component as a d-axis target harmonic component; Calculating a difference between the q-axis current prediction value and the q-axis target fundamental component as a q-axis target harmonic component, wherein the d-axis target harmonic component and the q-axis target harmonic component jointly constitute the target harmonic component; Determining the target fundamental wave component of the motor at the K+1 time includes: Acquire the initial fundamental wave component of the motor at the time K, wherein the initial fundamental wave component includes: a d-axis initial fundamental wave component and a q-axis initial fundamental wave component; Processing the d-axis current prediction value and the d-axis initial fundamental component based on a preset low-pass filter to obtain the d-axis target fundamental component; Processing the q-axis current prediction value and the q-axis initial fundamental component based on the low-pass filter to obtain the q-axis target fundamental component; The third determination module is specifically used for: A current harmonic separation controller is constructed to obtain the target harmonic component, where the current harmonic separation controller expression includes: in, They represent the fundamental component expressions of the predicted current at time k+1 on the d-axis and q-axis respectively, They represent the fundamental component expressions of the predicted current at time k on the d-axis and q-axis respectively, are the predicted current values ​​at time k+1 on the d-axis and q-axis respectively; The d-axis target harmonic component and the q-axis target harmonic component are expressed as: in, Respectively represent the harmonic component expressions of the predicted current at time k+1 on the d-axis and q-axis; The target cost function is expressed as: Among them, term1 is the current harmonic suppression term, term2 is the switching frequency limit term, H1 is the harmonic suppression factor, λ2 is the switching frequency limit factor, Represented as given currents on the d-axis and q-axis respectively.

7. A computer device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: in, The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 5.

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