Current control method and system for permanent magnet synchronous motor

Abstract

The present application discloses a high dynamic response current control method and system for a permanent magnet synchronous motor, and relates to the field of motor control technology. The method constructs a mathematical model of a permanent magnet synchronous motor based on a dq coordinate system, and determines a given voltage calculation equation for an extended prediction step length according to the mathematical model of the permanent magnet synchronous motor. Afterwards, a current controller is constructed according to the given voltage calculation equation for the extended prediction step length and the incremental deadbeat current prediction control equation, and a dq axis voltage given value is obtained according to the current controller. Finally, the dq axis voltage given value is subjected to space vector pulse width modulation to generate a switching signal to control the inverter to output a corresponding voltage to act on the permanent magnet synchronous motor and control the current of the permanent magnet synchronous motor. Compared with the prior art, the high dynamic response current control method for a permanent magnet synchronous motor proposed in the present application can improve the dynamic performance of the current control of the permanent magnet synchronous motor and has strong robustness.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a current control method and system for a permanent magnet synchronous motor. Background Art

[0002] The control system of a permanent magnet synchronous motor consists of three control loops, position, speed and torque, cascaded from the outside to the inside. Among them, the control of the motor position, speed and acceleration is essentially the control of the electromagnetic torque, and the high-performance control of the electromagnetic torque is usually achieved through the control of the current. In order to adapt to the complex and changing industrial environment, the industrial application of permanent magnet synchronous motors also puts forward strong robustness performance requirements for the current loop on the basis of high control accuracy, high dynamic response and low torque pulsation. Therefore, high-performance control of the current of the permanent magnet synchronous motor is a key factor in achieving high performance of the motor control system.

[0003] The deadbeat current prediction control method in the prior art is easily affected by factors such as parameter mismatch caused by measurement errors or time-varying parameters in the actual system, delays that are difficult to accurately model or compensate, and inverter nonlinearity, which in turn leads to the generation of current static errors, a decrease in dynamic response, and even system instability. In addition, the deadbeat current prediction control method ideally delays the current by two control cycles to follow the given high dynamic response, which places high demands on the system's voltage margin. When the calculated given voltage cannot be adjusted to act on the controlled motor due to insufficient voltage margin in the actual system, it needs to be limited and the delay of the current following the given will be extended to several or even dozens of control cycles. In this case, the dynamic response of the current and torque will also decrease. Summary of the invention

[0004] In order to address the deficiencies of the prior art, the purpose of the present application is to provide a current control method and system for a permanent magnet synchronous motor, which can improve the dynamic performance of the current control of the permanent magnet synchronous motor.

[0005] To achieve the above objectives, this application adopts the following technical solutions:

[0006] In the first aspect, the present application provides a high dynamic response current control method for a permanent magnet synchronous motor, the method comprising: constructing a mathematical model of the permanent magnet synchronous motor based on a dq coordinate system; determining a given voltage calculation equation for an extended prediction step according to the mathematical model of the permanent magnet synchronous motor; constructing a current controller according to the given voltage calculation equation for the extended prediction step and an incremental zero-beat current prediction control equation; inputting the dq-axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle into the current controller to obtain a dq-axis voltage given value for the next control cycle; performing space vector pulse width modulation on the dq-axis voltage given value to generate a switching signal and send it to an inverter, the switching signal being used to control the inverter to output a corresponding voltage to act on the permanent magnet synchronous motor to control the current of the permanent magnet synchronous motor.

[0007] Furthermore, a mathematical model of the permanent magnet synchronous motor is constructed based on the dq coordinate system, including: constructing an accurate discretized mathematical model of the permanent magnet synchronous motor according to the standard state space equation in the dq coordinate system, and the accurate discretized mathematical model of the permanent magnet synchronous motor satisfies the following relationship:

[0008] ,

[0009] in: represents the dq axis current at time k+1; , represents the dq axis current at time k; , represents the dq axis voltage at time k; , , , , , , , , , is the stator resistance, represents the rotor flux, represents the d-axis inductance, represents the q-axis inductance, represents the control cycle, represents the electrical angular velocity, The following relationship is satisfied:

[0010] ,

[0011] in: , , , ;

[0012] The mathematical model of the permanent magnet synchronous motor is simplified by voltage compensation to obtain the mathematical model of the permanent magnet synchronous motor. The mathematical model of the permanent magnet synchronous motor satisfies the following relationship:

[0013] ,

[0014] in: .

[0015] Furthermore, the given voltage calculation equation of the extended prediction step satisfies the following relationship:

[0016] ,

[0017] in: represents the duration of the entire dynamic process, , , the superscript * indicates the given value of the dq axis current or voltage, and the superscript ^ indicates the estimated value of the dq axis current or the matrix value is calculated using the estimated value of the motor parameter. Indicates the DC bus voltage.

[0018] Furthermore, according to the given voltage calculation equation of the extended prediction step and the incremental deadbeat current prediction control equation, a current controller is constructed, including: determining the incremental deadbeat current prediction control equation; judging whether the result of the incremental deadbeat current prediction control equation is less than or equal to a preset threshold; if the judgment result is no, iteratively calculating the given voltage calculation equation of the extended prediction step, and constructing the current controller in combination with the voltage compensation calculation equation; if the judgment result is yes, constructing the current controller through the incremental deadbeat current prediction control equation and the voltage compensation calculation equation; wherein the voltage compensation calculation equation satisfies the following relationship:

[0019] ,

[0020] Represents the given value of the dq-axis voltage in the k+1th control period after compensation.

[0021] Further, the incremental deadbeat current prediction control equation is determined, including: calculating the feedback value of the dq axis incremental current at time k:

[0022] ,

[0023] Calculate the estimated value of the dq axis incremental current at time k+1:

[0024] ,

[0025] Calculate the estimated value of the dq axis current at time k+1:

[0026] ,

[0027] Calculate the given value of the dq axis incremental voltage in the k+1th control cycle:

[0028] ,

[0029] Calculate the given value of the dq axis voltage in the k+1th control cycle before limiting:

[0030] ,

[0031] in: , represents the feedback value of the dq-axis incremental current at time k; , represents the estimated value of the dq-axis incremental current at time k+1; , represents the given value of the dq-axis incremental voltage in the kth control cycle; represents an adjustable robust factor matrix, where ; , represents the estimated value of the dq-axis current at time k; , represents the given value of dq axis current at time k; , represents the given value of the dq axis voltage in the k+1th control period before limiting; , represents the given value of the dq-axis voltage in the kth control cycle after limiting.

[0032] Further, the given voltage calculation equation of the extended prediction step is iteratively calculated, including: calculating the duration of the dynamic process Initial value of:

[0033] ,

[0034] Perform iterative calculation according to the preset number of iterations:

[0035] ,

[0036] in: Indicates the current iteration round, the superscript Indicates The result of the iterative calculation is represents the total number of iterations,

[0037] Perform minimum phase error limiting on the result of iterative calculation:

[0038] .

[0039] Furthermore, the dq axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle are input into the current controller to obtain the dq axis voltage given value of the next control cycle, including: obtaining the dq axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle; inputting the dq axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle into the current controller, and Perform voltage compensation and output the dq axis voltage reference value of the next control cycle after voltage compensation .

[0040] Furthermore, space vector pulse width modulation is performed according to the given value of the dq axis voltage, and a switching signal is generated and sent to the inverter, including: performing a coordinate transformation between two-phase coordinate systems on the given value of the motor dq axis voltage according to the electrical angle position of the permanent magnet synchronous motor rotor to obtain a given value of the motor axis voltage in a stationary two-phase coordinate system; space vector pulse width modulation is performed according to the given value of the motor axis voltage in the stationary two-phase coordinate system, and a corresponding switching signal is generated and sent to the inverter.

[0041] In a second aspect, the present application provides a high dynamic response current control system for a permanent magnet synchronous motor, the system comprising: a permanent magnet synchronous motor; a current sensor, the current sensor being used to sample the three-phase current of the permanent magnet synchronous motor stator at time k ; Position sensor, which is used to sample the mechanical angle position of the motor rotor at time k ; Current controller, the current controller is used to set the given value of the dq axis current of the permanent magnet synchronous motor at time k in the kth control cycle , feedback value And the feedback value of electrical angular velocity As input, calculate and output the given value of the dq axis voltage in the k+1th control cycle ; Space vector pulse width modulator, space vector pulse width modulator is used to adjust the given value of dq axis voltage Modulation generates the corresponding switching signal ; Inverter, the inverter is used to output the corresponding voltage to act on the permanent magnet synchronous motor under the control of the switching signal.

[0042] In a third aspect, the present application provides an electronic device, comprising: a memory and a processor, wherein the memory stores computer program instructions, and the processor is configured to execute the instructions stored in the memory to perform the method steps of the above-mentioned first aspect.

[0043] In a fourth aspect, a computer-readable storage medium is provided, which may be a readable non-volatile storage medium. The computer-readable storage medium stores computer instructions or programs, and when the computer-readable storage medium is run on a computer, the computer can execute the first aspect or any possible design method of the above aspects.

[0044] Based on the above scheme, the present application proposes a high dynamic response current control method for a permanent magnet synchronous motor, which constructs a mathematical model of a permanent magnet synchronous motor based on a dq coordinate system, and determines a given voltage calculation equation for an extended prediction step length according to the mathematical model of the permanent magnet synchronous motor. Afterwards, a current controller is constructed according to the given voltage calculation equation for the extended prediction step length and the incremental deadbeat current prediction control equation, and the dq axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle are input into the current controller to obtain the dq axis voltage given value of the next control cycle. Finally, space vector pulse width modulation is performed according to the dq axis voltage given value, a switching signal is generated and sent to the inverter, and the inverter is controlled to output a corresponding voltage to act on the permanent magnet synchronous motor to control the current of the permanent magnet synchronous motor. Compared with the prior art, the high dynamic response current control method for a permanent magnet synchronous motor proposed in the present application can improve the dynamic performance of the current control of the permanent magnet synchronous motor and has strong robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of a flow chart of a high dynamic response current control method for a permanent magnet synchronous motor provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of a current controller provided in an embodiment of the present application;

[0048] Figure 4 A schematic structural diagram of a high dynamic response current control system for a permanent magnet synchronous motor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the specific implementation manner of the present application will be clearly and completely described below in conjunction with the drawings in the implementation manner of the present application.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the embodiments of the present application as detailed in the attached claims.

[0051] It should also be understood that the term “comprising” indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements and / or components.

[0052] The high dynamic response current control method and system of the permanent magnet synchronous motor provided in the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0053] It is understandable that the high dynamic response current control method of the permanent magnet synchronous motor can be executed by any electronic device with computing capability. Figure 1 FIG. 1 is a block diagram of an electronic device 100 provided in an embodiment of the present application. Figure 1 As shown, the electronic device 100 includes but is not limited to: a processor 101 and a memory 102 .

[0054] The memory 102 is used to store executable instructions of the processor 101. It can be understood that the processor 101 is configured to execute instructions to implement the high dynamic response current control method of the permanent magnet synchronous motor in the above embodiment.

[0055] It should be noted that those skilled in the art can understand that Figure 1 The structure of the electronic device 100 shown in the figure does not constitute a limitation on the electronic device 100. The electronic device 100 may include Figure 1 More or fewer components may be shown, or certain components may be combined, or the components may be arranged differently.

[0056] The processor 101 is the control center of the electronic device 100, and uses various interfaces and lines to connect various parts of the entire electronic device 100. By running or executing software programs and / or modules stored in the memory 102, and calling data stored in the memory 102, the processor 101 performs various functions of the electronic device 100 and processes data, thereby monitoring the electronic device 100 as a whole. Optionally, the processor 101 can integrate an application processor and a modem processor.

[0057] The memory 102 may be used to store software programs and various data. The memory 102 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one functional module, etc. In addition, the memory 102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0058] It should be noted that the executor of the high dynamic response current control method for a permanent magnet synchronous motor provided in the present application is an electronic device, and may also be a chip or a system on chip, without limitation.

[0059] The embodiments of the present application do not limit the application scenarios of electronic devices. The business scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. It is known to those skilled in the art that with the evolution of technology and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0060] Figure 2 is a flow chart of a high dynamic response current control method for a permanent magnet synchronous motor provided in an embodiment of the present application, such as Figure 2 As shown, the high dynamic response current control method of the permanent magnet synchronous motor includes the following steps:

[0061] S201. Construct a mathematical model of the permanent magnet synchronous motor based on the dq coordinate system.

[0062] Among them, the dq coordinate system is a rotating coordinate system used in permanent magnet synchronous motors, which is used to simplify the control and analysis process of permanent magnet synchronous motors.

[0063] As an implementation method, the electronic device 100 constructs an accurate discretized permanent magnet synchronous motor mathematical model in the dq coordinate system according to the standard state space equation. The constructed accurate discretized permanent magnet synchronous motor mathematical model satisfies the following relationship:

[0064] ,

[0065] in: , , , represents the dq axis current, represents the dq axis voltage, represents the electrical angular velocity, is the stator resistance, represents the rotor flux, and They represent the d-axis and q-axis inductances respectively.

[0066] When the matrix A is a constant matrix, the exact solution of the state space equation in the continuous time domain satisfies the following relationship:

[0067] ,

[0068] in: is the starting time of current calculation, is the target time for current calculation, is the integration variable.

[0069] Further, and Substituting into the above formula, we can get the control period As discrete steps The exact discretization expression is as follows:

[0070] ,

[0071] Due to the control cycle Short enough, the electrical angular velocity It remains unchanged in several adjacent control cycles, so and It can be regarded as a constant matrix in the kth control cycle.

[0072] In addition, since the inverter output voltage has a zero-order holding effect in the αβ stationary coordinate system, the αβ axis voltage It remains unchanged in the kth control cycle and satisfies the following relationship:

[0073] ,

[0074] Therefore, considering the zero-order holding effect of the inverter, the actual voltage applied during the rotation process of the kth control cycle is Should be expressed as:

[0075] ,

[0076] Where: coordinate transformation matrix .

[0077] Will and Substituting the expression of into the dq coordinate system, the mathematical model of the permanent magnet synchronous motor with accurate discretization can be obtained. The mathematical model of the permanent magnet synchronous motor with accurate discretization satisfies the following relationship:

[0078] ,

[0079] in: , , , .

[0080] To obtain The explicit expression of the exact discretization result requires further solution This integral term. Based on the equivalent transformation of the matrix, we have:

[0081] ,

[0082] in: , .

[0083] The expression requires Reversible, that is , we can get The explicit expression of is as follows:

[0084] .

[0085] because , can be further Simplified to:

[0086] ,

[0087] Applying the Cayley-Hamilton theorem, we can get The explicit expression of is as follows:

[0088] ,

[0089] in: , , , .

[0090] It should be noted that for The surface mounted permanent magnet synchronous motor has:

[0091] ,

[0092] Furthermore, the electronic device 100 simplifies the precise discretized permanent magnet synchronous motor mathematical model through voltage compensation to obtain a permanent magnet synchronous motor mathematical model, and the permanent magnet synchronous motor mathematical model satisfies the following relationship:

[0093] ,

[0094] in: .

[0095] S202. Determine a given voltage calculation equation for an extended prediction step size according to a mathematical model of the permanent magnet synchronous motor.

[0096] As a way of implementation, in order to obtain the duration of the entire dynamic process As an accurate discretized motor model with discrete steps, assuming the electrical angular velocity The control law that keeps the dq axis voltage constant during the whole dynamic process is adopted to simplify the analysis, thus obtaining The expression of dq axis current at the moment is as follows:

[0097] ,

[0098] Further, by rearranging the discrete step lengths to of The exact discretization expression is: It is expressed as follows:

[0099] ,

[0100] Substituting into The expression for the dq axis current at the moment when it does not directly contain the rotor flux is as follows:

[0101] .

[0102] Furthermore, the principle of the given voltage calculation equation for determining the extended prediction step size is to calculate a dq axis voltage that remains constant throughout the dynamic process. , under its action, the dq axis current from Change to Time , and use this voltage value as And the amplitude of the given voltage vector should be maximized in the linear modulation region of the space vector pulse width modulation to minimize , to obtain the fastest dynamic response speed under this control law, so as to obtain the given voltage calculation equation of the extended prediction step, which satisfies the following relationship:

[0103] ,

[0104] in: , ; The superscript * indicates the given value of the dq axis current or voltage, and the superscript ^ indicates that the estimated value or matrix value of the dq axis current is calculated using the estimated value of the motor parameter. Indicates the DC bus voltage.

[0105] S203, constructing a current controller according to a given voltage calculation equation of an extended prediction step and an incremental deadbeat current prediction control equation.

[0106] As an implementation method, the electronic device 100 first calculates the incremental deadbeat current prediction control equation, including: calculating the feedback value of the dq axis incremental current at time k:

[0107] ,

[0108] Calculate the estimated value of the dq axis incremental current at time k+1:

[0109] ,

[0110] Calculate the estimated value of the dq axis current at time k+1:

[0111] ,

[0112] Calculate the given value of the dq axis incremental voltage in the k+1th control cycle:

[0113] ,

[0114] Calculate the given value of the dq axis voltage in the k+1th control cycle before limiting:

[0115] .

[0116] Furthermore, if Figure 3 As shown, the electronic device 100 determines whether the result of the incremental deadbeat current prediction control equation is less than or equal to a preset threshold. If the judgment result is no, the given voltage calculation equation with the extended prediction step is iteratively calculated, and a current controller is constructed in combination with the voltage compensation calculation equation. If the judgment result is yes, the current controller is constructed by the incremental deadbeat current prediction control equation and the voltage compensation calculation equation. For example, the preset threshold can be .

[0117] Among them, the voltage compensation calculation equation satisfies the following relationship:

[0118] ,

[0119] Represents the given value of the dq-axis voltage in the k+1th control period after compensation.

[0120] Furthermore, the electronic device 100 performs iterative calculation on a given voltage calculation equation of an extended prediction step length, including:

[0121] Calculate the duration of a dynamic process The initial value of satisfies the following relationship:

[0122] ,

[0123] The iterative calculation according to the set number of iterations satisfies the following relationship:

[0124] ,

[0125] in: Indicates the current iteration round, the superscript Indicates The result of the iterative calculation is represents the total number of iterations,

[0126] The minimum phase error limit of the iterative calculation result satisfies the following relationship:

[0127] .

[0128] S204, inputting the dq axis current given value, feedback value and electrical angular velocity feedback value of the permanent magnet synchronous motor in the current cycle into the current controller to obtain the dq axis voltage given value of the next control cycle.

[0129] As an implementation method, the electronic device 100 samples the given value of the dq axis current of the permanent magnet synchronous motor at time k in the kth control cycle. , feedback value And the feedback value of electrical angular velocity As the input of the current controller, the incremental deadbeat current prediction control part of the current controller calculates the given value of the dq axis voltage in the k+1th control cycle before limiting according to the control equation The voltage limiting part of the current controller is Perform amplitude limiting and calculate the given value of the dq axis voltage in the k+1th control cycle after amplitude limiting The voltage compensation part of the current controller is Compensation is performed and the given value of the dq axis voltage in the k+1th control cycle after compensation is output .

[0130] Among them, the given value of the motor dq axis current is Sent by the previous stage speed controller or preset. Estimated value of dq axis inductance , and an estimate of the stator resistance , are obtained in advance through offline measurement. The electrical angular velocity feedback value of the motor By measuring the rotor electrical angle position Differentiate to obtain the electrical angle position of the motor rotor The mechanical angle position of the rotor is measured by the position sensor After sampling, multiply it by the motor pole pair number p to obtain the dq axis current feedback value The stator three-phase current is measured by the current sensor After sampling, combined with the rotor electrical angle position It is obtained by transforming the coordinates from the stationary three-phase coordinate system to the rotating two-phase coordinate system.

[0131] S205 , performing space vector pulse width modulation on the given value of the dq axis voltage, generating a switching signal and sending it to the inverter.

[0132] Among them, space vector pulse width modulation usually generates a series of voltage vectors to approximate the ideal rotating magnetic field by accurately controlling the on and off time of the inverter switch, which is used to reduce the distortion of the current waveform and torque pulsation.

[0133] The switch signal is used to control the inverter to output a corresponding voltage to act on the permanent magnet synchronous motor to control the current of the permanent magnet synchronous motor.

[0134] As an implementation method, according to the given value of the motor dq axis voltage based on the permanent magnet synchronous motor rotor electrical angle position, the rotating two-phase coordinate system is transformed into a stationary two-phase coordinate system to obtain the given value of the motor αβ axis voltage Afterwards, the electronic device 100 Perform space vector pulse width modulation to generate corresponding switching signals and send them to the inverter.

[0135] Based on the above scheme, the present application proposes a high dynamic response current control method for a permanent magnet synchronous motor, which constructs a mathematical model of the permanent magnet synchronous motor based on the dq coordinate system, and determines the given voltage calculation equation of the extended prediction step according to the mathematical model of the permanent magnet synchronous motor. Afterwards, a current controller is constructed according to the given voltage calculation equation of the extended prediction step and the incremental deadbeat current prediction control equation, and the dq axis current given value, feedback value and feedback value of the electrical angular velocity of the permanent magnet synchronous motor in the current cycle are input into the current controller to obtain the dq axis voltage given value of the next control cycle. Finally, space vector pulse width modulation is performed according to the dq axis voltage given value, a switching signal is generated and sent to the inverter, and the inverter is controlled to output the corresponding voltage to act on the permanent magnet synchronous motor to control the current of the permanent magnet synchronous motor. Compared with the prior art, the high dynamic response current control method for permanent magnet synchronous motor proposed in this application does not require rotor flux parameters, and can follow the given high dynamic response with a current delay of two control cycles when the voltage margin is sufficient. When the voltage margin is insufficient, the dynamic response of current and torque can be significantly improved by replacing the traditional minimum phase error voltage limiting strategy with an extended prediction step size, and the current loop system controlled by the proposed method has strong robustness.

[0136] Figure 4 It is a structural schematic diagram of a high dynamic response current control system of a permanent magnet synchronous motor provided in an embodiment of the present application.

[0137] like Figure 4 As shown, the high dynamic response current control system of the permanent magnet synchronous motor includes: a permanent magnet synchronous motor, a current sensor, a position sensor, a current controller, a space vector pulse width modulator and an inverter.

[0138] Among them, the current sensor is used to sample the stator three-phase current of the table-mounted or built-in permanent magnet synchronous motor at time k ; The position sensor is used to sample the mechanical angle position of the motor rotor at time k The current controller is used to set the given value of the dq axis current of the permanent magnet synchronous motor at time k in the kth control cycle. , feedback value And the feedback value of electrical angular velocity As input, calculate and output the given value of the dq axis voltage in the k+1th control cycle ; The space vector pulse width modulator is used to adjust the motor dq axis voltage according to the given value Modulation generates the corresponding switching signal ; The inverter is used to output the corresponding voltage to act on the permanent magnet synchronous motor under the control of the switching signal.

[0139] Alternatively, those skilled in the art should easily appreciate that, in conjunction with the algorithmic steps of each example described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a function is performed in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0140] It should be noted that the method proposed in the present application can be stored in a computer-readable storage medium, and the readable storage medium can be a non-temporary computer-readable storage medium. For example, the non-temporary computer-readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device.

[0141] In an exemplary embodiment, the present application also provides a computer program product including one or more instructions, and the one or more instructions can be executed by the electronic device 100 to complete the method in the above embodiment.

[0142] It should be noted that when the instructions in the above-mentioned computer-readable storage medium or one or more instructions in the computer program product are executed by the electronic device 100, the various processes of the above-mentioned method embodiment are implemented, and the same technical effect as the above-mentioned method can be achieved. To avoid repetition, they will not be repeated here.

[0143] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above.

[0144] The units described as separate components may or may not be physically separated, and the components shown as units may be one physical unit or multiple physical units, that is, they may be located in one place or distributed in multiple different places. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0145] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0146] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application is essentially or the part that contributes to the prior art or the full classification part or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a single-chip microcomputer, chip, etc.) or a processor (processor) to execute the full classification part or part of the steps of each embodiment method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD and other media that can store program code.

[0147] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A current control method for a permanent magnet synchronous motor, characterized in that: The method comprises: Constructing a mathematical model of the permanent magnet synchronous motor based on a dq coordinate system; According to the mathematical model of the permanent magnet synchronous motor, the duration of the entire dynamic process is determined As the predicted step length for a given voltage, the equation is calculated as follows: is the dq axis current from Change to When used, and get the voltage value The amplitude of the given voltage vector should be maximized in the linear modulation region of the space vector pulse width modulation to minimize the duration ; Constructing a current controller according to a given voltage calculation equation of the prediction step length and an incremental deadbeat current prediction control equation; Inputting the dq axis current given value, feedback value and electrical angular velocity feedback value of the permanent magnet synchronous motor in the current cycle into the current controller to obtain the dq axis voltage given value of the next control cycle; The dq axis voltage given value is subjected to space vector pulse width modulation to generate a switching signal and send it to the inverter, wherein the switching signal is used to control the inverter to output a corresponding voltage to act on the permanent magnet synchronous motor to control the current of the permanent magnet synchronous motor.

2. The current control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The mathematical model of the permanent magnet synchronous motor is constructed based on the dq coordinate system, comprising: In the dq coordinate system, an accurate discretized permanent magnet synchronous motor mathematical model of the permanent magnet synchronous motor is constructed according to the standard state space equation, and the accurate discretized permanent magnet synchronous motor mathematical model satisfies the following relationship: ， in: represents the dq axis current at time k+1; , represents the dq axis current at time k; , represents the dq axis voltage at time k; , , ; , , , , , ; is the stator resistance, represents the rotor flux, represents the d-axis inductance, represents the q-axis inductance, represents the control cycle, represents the electrical angular velocity, The following relationship is satisfied: ， in: , , , ; The mathematical model of the permanent magnet synchronous motor which is precisely discretized is simplified by voltage compensation to obtain the mathematical model of the permanent magnet synchronous motor, which satisfies the following relationship: ， in: .

3. The current control method of a permanent magnet synchronous motor according to claim 2, characterized in that: The given voltage calculation equation of the prediction step size satisfies the following relationship: ， in: represents the duration of the entire dynamic process, , , the superscript * indicates the given value of the dq axis current or voltage, and the superscript ^ indicates the estimated value of the dq axis current or the matrix value is calculated using the estimated value of the motor parameter. Indicates the DC bus voltage.

4. The current control method of a permanent magnet synchronous motor according to claim 2, characterized in that: The current controller is constructed according to the given voltage calculation equation of the prediction step length and the incremental deadbeat current prediction control equation, including: Determining the incremental deadbeat current prediction control equation; Determining whether a result of the incremental deadbeat current prediction control equation is less than or equal to a preset threshold; If the judgment result is no, iteratively calculating the given voltage calculation equation of the prediction step length, and constructing the current controller in combination with the voltage compensation calculation equation; If the judgment result is yes, the current controller is constructed by an incremental deadbeat current prediction control equation and a voltage compensation calculation equation; wherein the voltage compensation calculation equation satisfies the following relationship: ， , represents the given value of the dq axis voltage in the k+1th control period after compensation; in, Represents the given value of the dq-axis voltage in the k+1th control cycle after limiting.

5. The current control method of a permanent magnet synchronous motor according to claim 4, characterized in that: The step of determining the incremental deadbeat current prediction control equation comprises: Calculate the feedback value of the dq axis incremental current at time k: ， Calculate the estimated value of the dq axis incremental current at time k+1: ； Calculate the estimated value of the dq axis current at time k+1: ， Calculate the given value of the dq axis incremental voltage in the k+1th control cycle: ； in, Represents a second-order matrix The inverse matrix of Calculate the given value of the dq axis voltage in the k+1th control cycle before limiting: ， in: , represents the feedback value of the dq-axis incremental current at time k; , represents the estimated value of the dq-axis incremental current at time k+1; , represents the given value of the dq-axis incremental voltage in the kth control cycle; represents an adjustable robust factor matrix, where ; , represents the estimated value of the dq-axis current at time k; , represents the given value of dq axis current at time k; , represents the given value of the dq axis voltage in the k+1th control period before limiting; , represents the given value of the dq-axis voltage in the kth control cycle after limiting.

6. The current control method of a permanent magnet synchronous motor according to claim 5, characterized in that: The iterative calculation of the given voltage calculation equation of the prediction step length comprises: Calculate the duration of a dynamic process Initial value of: ， Perform iterative calculation according to the preset number of iterations: ， in: Indicates the current iteration round, the superscript Indicates The result of the iterative calculation is Indicates the total number of iterations; Perform minimum phase error limiting on the result of iterative calculation: 。 7. The current control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The step of inputting the dq axis current given value, feedback value and electrical angular velocity feedback value of the permanent magnet synchronous motor in the current cycle into the current controller to obtain the dq axis voltage given value of the next control cycle includes: Obtaining the dq axis current set value, feedback value and electrical angular velocity feedback value of the permanent magnet synchronous motor in the current cycle; The dq axis current given value, feedback value and electrical angular velocity feedback value of the permanent magnet synchronous motor in the current cycle are input into the current controller, and Perform voltage compensation and output the dq axis voltage reference value of the next control cycle after voltage compensation ; in, Represents the given value of the dq-axis voltage in the k+1th control cycle after limiting.

8. The current control method of a permanent magnet synchronous motor according to claim 1, characterized in that: The step of performing space vector pulse width modulation on the given value of the dq axis voltage to generate a switching signal and sending the switching signal to the inverter includes: According to the electrical angle position of the permanent magnet synchronous motor rotor, a given value of the motor dq axis voltage is subjected to coordinate transformation between two-phase coordinate systems to obtain a given value of the shaft voltage of the permanent magnet synchronous motor in a stationary two-phase coordinate system; Space vector pulse width modulation is performed according to a given value of the shaft voltage of the permanent magnet synchronous motor in a stationary two-phase coordinate system, and a corresponding switching signal is generated and sent to the inverter.

9. An electronic device, characterized in that: include: The method comprises a memory and a processor, wherein the memory stores computer program instructions, and the processor is configured to execute the instructions stored in the memory to perform the method steps according to any one of claims 1 to 8.

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