Control method and device of permanent magnet synchronous motor, control system and power system

Abstract

According to the control method, the control device, the control system and the power system of the permanent magnet synchronous motor, the high-frequency injection mode is adopted in the starting process, the flux linkage observation mode is adopted after operation, and the starting current and the initial position angle of the motor required for operating the flux linkage observation mode of the motor are determined in the high-frequency injection mode; and the starting of the motor is smoother.

Description

Technical Field

[0001] The present application relates to the field of motors, and in particular to a control method, a control device, a control system and a power system for a permanent magnet synchronous motor. Background Art

[0002] Permanent magnet synchronous motors are widely used in electric vehicles, such as 3T logistics vehicles. They have the characteristics of large power factor, high torque-to-inertia ratio, high power density, simple structure and easy maintenance. They are widely used in servo systems, industrial control and other fields. In the control of permanent magnet synchronous motors, in order to observe the rotor position and speed information, mechanical sensors (Hall sensors, rotary transformers, grating encoders, etc.) need to be installed on the motor to achieve closed-loop control of the motor. Installing a position sensor on the motor body will increase the size of the motor, make the structure of the control system more complicated, and make it inconvenient to maintain. It will also reduce the stability of the system and deteriorate the anti-interference ability. At the same time, the sensor has specific applicable conditions and can only operate under appropriate conditions. In some harsh environments, the sensor cannot be used normally.

[0003] Therefore, many permanent magnet synchronous motors now use position sensorless control methods to reduce motor costs and improve system stability.

[0004] At present, field-oriented control (FOC) is one of the common methods for controlling permanent magnet synchronous motors. Through field-oriented control, the stator current of the permanent magnet synchronous motor can be decoupled into the excitation current and the torque current, and they can be controlled separately, so as to achieve precise control of the torque and speed of the motor. Field-oriented control requires the position and speed information of the rotor in order to accurately control the excitation current and the torque current; at the same time, according to the position and speed information of the rotor, the speed loop and the current loop of the motor can also be adjusted and controlled accordingly. In order to achieve precise control of the permanent magnet synchronous motor, it is necessary to use a suitable estimation method to obtain accurate rotor position and speed information and apply it to field-oriented control.

[0005] Currently, some people have proposed to use a high-frequency injection algorithm to operate the motor at medium and low speeds during the starting process of the permanent magnet synchronous motor (for example: CN117914202, CN116436364). However, the above method will cause the motor to generate fixed-frequency current harmonic noise during the starting process, especially in the medium and low speed stages due to high-frequency injection. In addition, the permanent magnet synchronous motor needs to switch algorithms at medium and low speeds during the starting process, resulting in excessive speed pulsation, leading to motor operation fluctuations and other problems.

[0006] To address the above problems, no effective solution has been proposed yet. Summary of the invention

[0007] In view of this, the present application proposes a control method, a control device, a control system and a power system for a permanent magnet synchronous motor (PMSM), which adopts a high-frequency injection mode in the starting preparation process and a flux observation mode after operation. In the high-frequency injection mode, the starting current and the initial position angle of the motor required for the flux observation mode of the motor operation are determined, thereby making the starting of the motor smoother.

[0008] According to one aspect of the present application, a control method for a permanent magnet synchronous motor is provided, characterized in that:

[0009] In response to the motor starting, a starting current and an initial position angle of the motor required for running a flux observation mode after the motor is running normally are determined by a voltage injection mode of injecting at least a high-frequency voltage into a d-axis in a two-phase rotating coordinate system;

[0010] Based on the starting current of the motor and the initial position angle of the flux observation mode, the α-axis voltage U of the input motor is determined. α and β-axis voltage U β ;

[0011] Based on U α and U β generating a switching signal for a three-phase inverter, wherein the three-phase inverter generates a current for controlling the rotation of the motor so that the motor operates normally, wherein the three-phase inverter is electrically connected to the motor;

[0012] In response to the motor operating normally, the operation of the motor is controlled by the flux observation mode.

[0013] Optionally, a starting current and an initial position angle of the motor required to run the flux observation mode after the motor runs normally are determined by injecting at least a high-frequency voltage into the d-axis in the two-phase rotating coordinate system, including:

[0014] Determining an estimated angle value of the motor by first injecting a periodic high-frequency square wave voltage;

[0015] By injecting a positive and negative high-frequency square wave voltage for the second time, the magnetic pole direction of the motor rotor is obtained;

[0016] Obtaining an actual position angle of the motor based on the magnetic pole direction of the motor rotor and the estimated angle value of the motor;

[0017] Based on the actual position angle of the motor, the reference current values ​​of the d-axis current value Id and the q-axis current value Iq when the motor starts are determined through calibration data;

[0018] The reference current values ​​of Id and Iq are used as the starting current of the motor required for the flux observation mode, and the actual position angle of the motor is used as the initial position angle of the motor required for the flux observation mode.

[0019] Optionally,

[0020] The calibration data includes the corresponding relationship between the motor angle and the motor d-axis current and q-axis current;

[0021] and / or,

[0022] By injecting a periodic high-frequency square wave voltage for the first time, determining an estimated angle value of the motor, including:

[0023] The injected high-frequency square wave voltage is subjected to Park inverse transformation and space vector pulse width modulation (SVPWM) module to obtain a switching signal for the three-phase inverter;

[0024] Obtaining current components in the three-phase lines of the motor, the current components are transformed by Clark and Park to obtain a d-axis current component id and a q-axis current component iq in a two-phase rotating coordinate system;

[0025] Performing bandwidth filtering on the q-axis current component iq to remove the harmonic current of the q-axis current component iq, and obtaining a high-frequency current value of the q-axis current component;

[0026] An estimated angle value of the motor is obtained based on the high-frequency current value and the injected high-frequency square wave voltage.

[0027] Optionally, obtaining an estimated angle value of the motor based on the high-frequency current value and the injected high-frequency square wave voltage includes:

[0028] Multiplying the high-frequency current value by the sign of the injected high-frequency square wave voltage to obtain a current value containing rotor position and speed information;

[0029] The current value containing the rotor position and speed information is passed through a low-pass filter and then transmitted to a phase-locked loop to obtain the current speed of the motor;

[0030] The current rotation speed of the motor is integrated to obtain the current estimated angle value of the motor.

[0031] Optionally, the magnetic pole direction of the motor rotor is obtained by injecting a positive and negative high-frequency square wave voltage for the second time, including:

[0032] By comparing the positive current peak value of the d-axis current component id obtained based on the injected square wave voltage, the magnetic pole direction of the motor rotor is obtained.

[0033] Optionally, based on U α and U β Generates switching signals for a three-phase inverter, including:

[0034] The obtained U α and Uβ The switching signals for the three-phase inverter are generated by the SVPWM module.

[0035] Optionally, controlling the operation of the motor through a flux observation mode includes:

[0036] Obtaining the current on the three-phase line of the motor;

[0037] Convert the three-phase current of the motor into the current signals of α and β axes through Clark transformation;

[0038] The voltage and current signals of the α and β axes are input into the permanent magnet flux observation module, and the estimated rotor position information of the angle between the permanent magnet flux amplitude and the motor angle required by the motor is obtained according to the stator voltage, stator current and three-phase winding resistance in the motor flux information;

[0039] Based on the estimated position information of the rotor, the speed signal of the motor is obtained through the flux observation module;

[0040] Integrate the speed signal to obtain the actual angle position signal of the motor;

[0041] The speed signal and the actual angle position signal of the motor are input into the motor control unit to control the rotation of the motor.

[0042] According to another aspect of the present application, a control device for a permanent magnet synchronous motor is provided, characterized in that it includes: a processor and a memory, the memory storing an executable program, and the processor executing the above-mentioned method based on the executable program.

[0043] According to another aspect of the present application, a control system for a permanent magnet synchronous motor is provided, characterized in that it includes:

[0044] A three-phase inverter and a control device as described above.

[0045] According to another aspect of the present application, a power system is provided, characterized in that it includes:

[0046] A permanent magnet synchronous motor and a control system as described above.

[0047] According to a control method, control device, control system and power system of a permanent magnet synchronous motor proposed in the present application, a high-frequency injection mode is adopted in the starting preparation process, a flux observation mode is adopted after operation, and the starting current and initial position angle of the motor required for the flux observation mode of the motor operation are determined in the high-frequency injection mode, thereby eliminating the noise of fixed-frequency current harmonics generated by operating the motor in the medium and low speed stages using the high-frequency injection algorithm during the motor starting process, and solving the problem of motor operation fluctuations caused by the need to switch algorithms during the medium and low speeds of the permanent magnet synchronous motor starting process, realizing full-speed range jitter-free starting control of the permanent magnet synchronous motor, making the motor start smoother and more efficient.

[0048] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0050] Figure 1 A schematic diagram showing an embodiment of a power system of the present application is shown;

[0051] Figure 2 A schematic diagram showing an embodiment of a control method for a permanent magnet synchronous motor of the present application is shown;

[0052] Figure 3 A schematic diagram showing an embodiment of calibration data of a control method for a permanent magnet synchronous motor of the present application;

[0053] Figure 4 A schematic diagram showing an embodiment of a high-frequency voltage injection method for a permanent magnet synchronous motor of the present application;

[0054] Figure 5 A schematic diagram showing an embodiment of a start-up solution process of a control method for a permanent magnet synchronous motor of the present application;

[0055] Figure 6 A schematic diagram showing an embodiment of a high frequency injection process in a control method for a permanent magnet synchronous motor of the present application is shown;

[0056] Figure 7 A schematic diagram of an embodiment of a flux observation process in a control method for a permanent magnet synchronous motor of the present application is shown. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0058] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention 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 interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0059] Figure 1 A schematic diagram of an embodiment of a power system of the present application is shown.

[0060] As shown in the figure, the power system includes a permanent magnet synchronous motor 1 and a control system 2, the control system 2 includes a control device 21 and a three-phase inverter 22, the control device 21 includes, for example, a processor and a memory, the memory stores an executable program, and the processor executes the control method of the present application for the permanent magnet synchronous motor 1 based on the executable program. The control device 21, the three-phase inverter 22 and the permanent magnet synchronous motor 1 are electrically connected to each other, and the three-phase inverter 22 generates a current for controlling the rotation of the motor 1 to make the motor run.

[0061] Figure 2 A schematic diagram showing an embodiment of a control method for a permanent magnet synchronous motor of the present application is shown.

[0062] Step S1 , in response to the motor starting, a starting current of the motor and an initial position angle of a flux observation mode for controlling the operation of the motor are determined by a voltage injection mode of injecting at least a high frequency voltage into a d-axis in a two-phase rotating coordinate system.

[0063] Step S2, based on the starting current of the motor and the initial position angle of the flux observation mode, determine the α-axis voltage U of the input motor α and β-axis voltage U β ;

[0064] Step S3, based on U αand U β generating a switching signal for a three-phase inverter, wherein the three-phase inverter generates a current for controlling the rotation of the motor to operate the motor, wherein the three-phase inverter is electrically connected to the motor;

[0065] Step S4, in response to the motor running, controlling the motor running by the flux observation mode.

[0066] A permanent magnet synchronous motor usually requires a preparation process from starting to formal operation. In the present application, in response to the start of the permanent magnet synchronous motor, such as the motor being powered on or obtaining a start instruction, in the start preparation stage, a voltage injection mode of injecting at least a high-frequency voltage is used to provide voltage to the motor, and after the motor is officially running (i.e., starting to rotate), a single flux observation mode (applying a flux observation algorithm) is used to control the operation of the motor. Among them, in the voltage injection mode of the start preparation stage, the starting current and initial position angle of the motor required for the motor to run the flux observation mode are determined, and the determined starting current and initial position angle are assigned to the flux observation algorithm for the next moment angle identification. Based on the scheme of the present application, the high-frequency injection algorithm is no longer used for the operation of the motor, so there is no noise, and the noise of the fixed-frequency current harmonics generated by the motor using the high-frequency injection algorithm to operate the motor in the medium and low speed stages during the motor start-up process is eliminated, and there is no need to switch the algorithm during the operation process, such as in the medium and low speed stages, which solves the problem that the permanent magnet synchronous motor needs to switch the algorithm at medium and low speeds during the start-up process, resulting in motor operation fluctuations, and realizes the full-speed domain jitter-free starting control of the permanent magnet synchronous motor, making the motor start smoother.

[0067] As an implementation method, in step S2, in the voltage injection mode, by injecting a periodic high-frequency square wave voltage for the first time (changing the amplitude of the injected voltage every half cycle, for example, injecting at least two cycles), the estimated angle value of the motor is determined; by injecting a section of positive and negative high-frequency square wave voltage for the second time, the magnetic pole direction (actual direction) of the motor rotor is obtained, and the second injection is not a periodic voltage, but a section of positive and negative high-frequency voltage. For example, a positive high-frequency voltage is first injected, and then a negative high-frequency voltage is injected after waiting for a period of time to ensure that the high-frequency current drops to zero; based on the magnetic pole direction of the motor rotor and the estimated angle value of the motor, the actual position angle of the motor is obtained; based on the actual position angle of the motor, the reference current values ​​of the d-axis current value Id and the q-axis current value Iq when the motor starts running are determined by calibration data; the reference current values ​​of Id and Iq are used as the starting current of the motor required for the flux observation mode, and the actual position angle of the motor is used as the initial position angle of the motor required for the flux observation mode.

[0068] The calibration data includes the correspondence between the motor angle and the motor d-axis starting current and q-axis starting current, which can be in the form of a table. The corresponding motor current value can be obtained by looking up the table according to the motor angle. Figure 3 A schematic diagram of an embodiment of calibration data of a control method for a permanent magnet synchronous motor of the present application is shown. The horizontal direction represents the angle, and the vertical direction represents the starting current value, which can be obtained by statistically analyzing the historical empirical data of the current magnitude of the motor starting at each angle obtained from past motor pair test.

[0069] As an implementation method, when the periodic high-frequency square wave voltage is injected for the first time, the injected high-frequency square wave voltage is subjected to Park inverse transformation and space vector pulse width modulation SVPWM module to obtain a switching signal for the three-phase inverter; then the current components in the three-phase lines of the motor are obtained, and the current components are subjected to Clark transformation and Park transformation to obtain a d-axis current component id and a q-axis current component iq in a two-phase rotating coordinate system; the q-axis current component iq is bandwidth filtered to remove the harmonic current of the q-axis current component iq, and the high-frequency current value of the q-axis current component is obtained; based on the high-frequency current value and the injected high-frequency square wave voltage, an estimated angle value of the motor is obtained. Figure 4 A schematic diagram of an embodiment of an injection high-frequency voltage control method for a permanent magnet synchronous motor of the present application is shown. As shown in the figure, the injected high-frequency square wave voltage is a square wave voltage of +Vinj and -Vinj, one cycle is T1+T2, the positive voltage duration is T1, and the negative voltage duration is T2. T1 and T2 can be the same or different, and the corresponding PWM pulse width modulation carrier is shown in the figure above.

[0070] As an example, based on the high-frequency current value and the injected high-frequency square wave voltage, the estimated angle value of the motor is obtained, which can be achieved as follows: multiply the high-frequency current value with the sign of the injected high-frequency square wave voltage to obtain a current value containing rotor position and speed information; pass the current value containing rotor position and speed information through a low-pass filter, and pass it into a phase-locked loop to obtain the current speed of the motor; integrate the current speed of the motor to obtain the current estimated angle value of the motor.

[0071] As an implementation method, after a second injection of a positive and negative high-frequency square wave voltage, the magnetic pole direction of the motor rotor (i.e., the actual rotation direction of the motor rotor) is obtained by comparing the positive current peak value of the d-axis current component id obtained based on the injected square wave voltage.

[0072] As an implementation method, in step S3, the obtained U α and U βThe SVPWM module further generates a switching signal for the three-phase inverter. The switching signal is, for example, a saddle wave, which is input into the three-phase inverter so that the three-phase inverter generates a current, such as a sinusoidal current, for controlling the operation of the motor to operate the motor.

[0073] As an implementation method, in step S4, the operation of the motor is controlled in the flux observation mode by the following steps:

[0074] Obtaining the current on the three-phase line of the motor;

[0075] Convert the three-phase current of the motor into the current signals of α and β axes through Clark transformation;

[0076] The voltage and current signals of the α and β axes are input into the permanent magnet flux observation module, and the angle between the permanent magnet flux amplitude and the motor angle required by the motor and the motor angle is obtained according to the stator voltage, stator current and three-phase winding resistance of the motor;

[0077] The speed signal of the motor is obtained through a flux observation module (such as a phase-locked loop or a flux observer);

[0078] Integrate the speed signal to obtain the actual angle position signal of the motor;

[0079] The speed signal and the actual angle position signal of the motor are input into the motor control unit to control the rotation of the motor.

[0080] Figure 5 A schematic diagram showing an embodiment of a start-up solution process of a control method for a permanent magnet synchronous motor of the present application is shown.

[0081] As shown in the figure, the entire global startup solution process:

[0082] Step S51, using a high frequency injection algorithm to identify the current position and angle of the motor.

[0083] In step S52, the current required for the current starting operation, such as the d-axis current Id and the q-axis current Iq, is obtained by looking up a table according to the identified motor angle.

[0084] Step S53, the angle obtained by high frequency injection is then used as the initial angle for flux observation.

[0085] Step S54, start the motor operation. From the beginning of the motor operation, the flux observation algorithm is used to achieve a single algorithm control of the entire motor domain, avoiding the motor speed fluctuation when switching algorithms during the operation of the permanent magnet synchronous motor and the noise problem generated when the motor is running with high frequency injection at medium and low speeds.

[0086] Figure 6A schematic diagram of an embodiment of a high-frequency injection process in a control method for a permanent magnet synchronous motor of the present application is shown.

[0087] When the motor starts (i.e., it receives a start command, but is not already rotating), a high-frequency square wave current and voltage (-1) is first injected into the d-axis of the two-phase rotating coordinate system. n Vinj, the cycle of the injected current and voltage can be expressed as Figure 4 As shown, the amplitude of the injected voltage is changed every half cycle; then, after Park's inverse transformation and SVPWM module, a switching signal for the inverter is obtained, which acts on the inverter to generate, for example, a sinusoidal current for controlling the rotation of the motor.

[0088] Then, the current component i acting on the three-phase line of the motor in the three-phase stationary coordinate system is obtained through a current sampling circuit (for example, it can be a sampling circuit in the motor driver, not shown). A 、i B 、i C , the three-phase current components are transformed by Clark and Park to obtain the current components id and iq in the two-phase rotating coordinate system; then the current component of the q axis is subjected to bandwidth filtering (BPF) to obtain the high-frequency current value without harmonic current, and the high-frequency current value is compared with the sign of the injected signal (Sgn((-1) n Vinj) (the q-axis current value is multiplied by the positive and negative signs of the injected current to eliminate the positive and negative currents caused by the injection of high-frequency positive and negative voltages) to obtain the current value containing the rotor position and speed information. The current value is then passed through a low-pass filter (LPF) and transmitted to the phase-locked loop (PLL) to obtain the current speed. The speed is integrated (1 / s) to obtain the estimated angle value of the required motor.

[0089] The magnetic pole direction of the rotor can be obtained by injecting positive and negative pulse signals and comparing the positive current peak of the ID axis to obtain the actual direction of the motor rotor. The actual position of the motor can be obtained by combining the magnetic pole direction and the estimated angle value of the motor.

[0090] After obtaining the actual position angle of the motor, the reference current values ​​of Id and Iq when the motor starts are obtained through calibration data (angle-motor starting current calibration table), where the calibration data query means as follows: Figure 3 As shown. The current values ​​of the d-axis and q-axis are used as the starting current of the motor; the actual position angle of the motor obtained above is used as the initial position angle of the flux observation; and the input motor U is calculated using the initial position angle of the motor and the obtained Id and Iq currents. α and U β Then get the U α and U βThe SVPWM module generates a saddle wave for switching the inverter, and inputs the saddle wave into the three-phase inverter, so that the three-phase inverter generates a sinusoidal current for controlling the operation of the motor, so that the motor operates normally.

[0091] Figure 7 A schematic diagram of an embodiment of a flux observation process in a control method for a permanent magnet synchronous motor of the present application is shown.

[0092] When the motor rotates, the current i on the three-phase line of the motor is obtained through current sampling. A 、i B 、i C , the three currents of the motor are converted into the current signals of α and β axes through Clark transformation α 、i β ; Input the voltage and current signals of the α and β axes into the flux observation module (as shown in the figure, the module includes Flux_Observer and PLL or observer), and obtain the estimated position information of the motor's rotor, such as the estimated rotor angle "θ", according to the stator voltage, stator current, three-phase winding resistance and voltage equation by the following formula.

[0093]

[0094] Among them, u α 、u β 、i α 、i β , R s They are stator voltage, stator current, three-phase winding resistance, ψ f is the amplitude of the permanent magnet flux, ψ α , β are the α and β axis flux amplitudes, L s is the equivalent inductance of the stator winding.

[0095] After obtaining the estimated position information of the rotor, the motor speed signal is obtained through the phase-locked loop or observer in the flux observation module, and the speed signal is integrated (1 / s) to obtain the actual angle position "θ" of the motor; the speed and angle signals are then input into the motor control to complete the control of the entire motor.

[0096] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0097] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0098] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A control method for a permanent magnet synchronous motor, characterized in that: In response to the motor starting, determining the starting current and initial position angle of the motor required for the motor running flux observation mode by injecting at least a high frequency voltage into the d-axis in the two-phase rotating coordinate system in a voltage injection mode; Based on the starting current of the motor and the initial position angle of the flux observation mode, the α-axis voltage U of the input motor is determined. α and β-axis voltage U β ; Based on U α and U β generating a switching signal for a three-phase inverter, wherein the three-phase inverter generates a current for controlling the rotation of the motor to operate the motor, wherein the three-phase inverter is electrically connected to the motor; In response to the operation of the motor, the operation of the motor is controlled by the flux observation mode.

2. The method according to claim 1, characterized in that The starting current and the initial position angle of the motor required for the motor to operate in the flux observation mode are determined by injecting at least a high frequency voltage into the d-axis in the two-phase rotating coordinate system, including: Determining an estimated angle value of the motor by first injecting a periodic high-frequency square wave voltage; By injecting a positive and negative high-frequency square wave voltage for the second time, the magnetic pole direction of the motor rotor is obtained; Obtaining an actual position angle of the motor based on the magnetic pole direction of the motor rotor and the estimated angle value of the motor; Based on the actual position angle of the motor, the reference current values ​​of the d-axis current value Id and the q-axis current value Iq when the motor starts are determined through calibration data; The reference current values ​​of Id and Iq are used as the starting current of the motor required for the flux observation mode, and the actual position angle of the motor is used as the initial position angle of the motor required for the flux observation mode.

3. The method according to claim 2, characterized in that: The calibration data includes the corresponding relationship between the motor angle and the motor d-axis current and q-axis current; and / or, By injecting a periodic high-frequency square wave voltage for the first time, determining an estimated angle value of the motor, including: The injected high-frequency square wave voltage is subjected to Park inverse transformation and space vector pulse width modulation (SVPWM) module to obtain a switching signal for the three-phase inverter; Obtaining current components in the three-phase lines of the motor, the current components are transformed by Clark and Park to obtain a d-axis current component id and a q-axis current component iq in a two-phase rotating coordinate system; Performing bandwidth filtering on the q-axis current component iq to remove the harmonic current of the q-axis current component iq, and obtaining a high-frequency current value of the q-axis current component; An estimated angle value of the motor is obtained based on the high-frequency current value and the injected high-frequency square wave voltage.

4. The method according to claim 3, characterized in that Based on the high-frequency current value and the injected high-frequency square wave voltage, an estimated angle value of the motor is obtained, including: Multiplying the high-frequency current value by the sign of the injected high-frequency square wave voltage to obtain a current value containing rotor position and speed information; The current value containing the rotor position and speed information is passed through a low-pass filter and then transmitted to a phase-locked loop to obtain the current speed of the motor; The current rotation speed of the motor is integrated to obtain the current estimated angle value of the motor.

5. The method according to claim 2, characterized in that By injecting a positive and negative high-frequency square wave voltage for the second time, the magnetic pole direction of the motor rotor is obtained, including: By comparing the positive current peak value of the d-axis current component id obtained based on the injected square wave voltage, the magnetic pole direction of the motor rotor is obtained.

6. The method according to claim 1, characterized in that Based on U α and U β Generates switching signals for a three-phase inverter, including: The obtained U α and U β The switching signals for the three-phase inverter are generated by the SVPWM module.

7. The method according to claim 1, characterized in that Controlling the operation of the motor through a flux observation mode includes: Obtaining the current on the three-phase line of the motor; Convert the three-phase current of the motor into the current signals of α and β axes through Clark transformation; Inputting the voltage and current signals of the α and β axes into the permanent magnet flux observation module, and obtaining the estimated position information of the rotor of the motor according to the stator voltage, stator current and three-phase winding resistance in the motor flux information; Based on the estimated position information of the rotor, the speed signal of the motor is obtained through the flux observation module; Integrate the speed signal to obtain the actual angle position signal of the motor; The speed signal and the actual angle position signal of the motor are input into the motor control unit to control the rotation of the motor.

8. A control device for a permanent magnet synchronous motor, characterized in that: include: A processor and a memory, wherein the memory stores an executable program, and the processor executes the method according to any one of claims 1 to 7 based on the executable program.

9. A control system for a permanent magnet synchronous motor, characterized in that: include: A three-phase inverter and a control device as claimed in claim 8.

10. A power system, characterized in that: include: A permanent magnet synchronous motor and a control system as claimed in claim 9.

Images