Permanent magnet synchronous motor VF control method, device, equipment and readable storage medium

Abstract

The present invention discloses a permanent magnet synchronous motor VF control method, device, equipment and readable storage medium, which relates to the field of motor control technology. The method comprises the following steps: step S10, obtaining the actual value of the reactive current and the actual value of the active current of the motor; step S20, determining the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, and determining the frequency compensation amount according to the actual value of the active current; step S30, compensating the output voltage according to the low-frequency voltage compensation amount, and compensating the output frequency according to the frequency compensation amount, and then controlling the motor operation according to the compensated output voltage and the compensated output frequency. On the one hand, the present invention improves the low-frequency operation stability and starting load capacity of the motor, and on the other hand, keeps the motor flux stable under no-load or light-load conditions, and provides sufficient terminal voltage under heavy-load conditions to ensure the smooth operation of the motor. When the present invention controls the operation of different motors, it is not necessary to repeatedly adjust the coefficient of the high-pass filter, and has strong adaptability.

Description

Technical Field

[0001] The present invention relates to the field of motor control technology, and in particular to a permanent magnet synchronous motor VF control method, device, equipment and readable storage medium. Background Art

[0002] In the field of heavy industrial drive, asynchronous motors and electrically excited synchronous motors are widely used. However, in recent years, permanent magnet synchronous motors have become increasingly common in all walks of life, and there is a trend of accelerating the replacement of asynchronous motors. Permanent magnet synchronous motors have the advantages of high energy density, small size, and high efficiency, which have extended the application of permanent magnet synchronous motors from light industry to heavy industry. Vector control is the most widely used control method in the field of permanent magnet synchronous motor control, especially closed-loop vector control with encoders, which can accurately measure the rotor position and speed, improve the motor control accuracy and phase response speed. However, in many industrial fields, due to the limitations of the working environment, there will be many problems in the installation of encoders, such as electromagnetic interference, encoder disconnection and other problems that will affect the stable operation of the equipment.

[0003] In the prior art, the VF control of permanent magnet synchronous motors does not require an encoder or the motor parameters required by the motor model, so it is simpler than motor vector control. The VF control of permanent magnet synchronous motors in the prior art mainly achieves frequency compensation through high-pass filtering of active power or active current, thereby stabilizing the operation of the motor. However, when this solution controls the operation of different motors, it is necessary to repeatedly adjust the coefficient of the high-pass filter, and the adaptability is poor. Summary of the invention

[0004] The embodiments of the present invention provide a permanent magnet synchronous motor VF control method, device, equipment and readable storage medium to solve the technical problem that the existing permanent magnet synchronous motor VF control method in the related art needs to repeatedly adjust the high-pass filter coefficient when controlling different motor operations, and has poor adaptability.

[0005] In a first aspect, a permanent magnet synchronous motor VF control method is provided, comprising the following steps:

[0006] Get the actual value of reactive current and active current of the motor;

[0007] Determine the low-frequency voltage compensation amount according to the actual value of reactive current and the preset reactive current given value, and determine the frequency compensation amount according to the actual value of active current;

[0008] The output voltage is compensated according to the low-frequency voltage compensation amount, and the output frequency is compensated according to the frequency compensation amount, and the motor operation is controlled according to the compensated output voltage and the compensated output frequency.

[0009] In some embodiments, the steps of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency include:

[0010] When the motor is running at low frequency, the low frequency voltage compensation amount is superimposed on the output voltage. When the motor operating frequency gradually increases, the low frequency voltage compensation amount is linearly reduced to zero according to the motor operating frequency.

[0011] In some embodiments, the step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency further includes:

[0012] The frequency compensation amount is superimposed on the output frequency and the frequency compensation amount is limited.

[0013] In some embodiments, the step of determining the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value includes:

[0014] According to the formula ΔV=Kp 1 ·(I d1 -I d0 ) calculating and determining the low frequency voltage compensation amount;

[0015] Among them, ΔV is the low-frequency voltage compensation; Kp 1 is the preset first proportionality coefficient; I d1 is the preset reactive current given value; I d0 is the actual value of reactive current.

[0016] In some embodiments, the step of determining the frequency compensation amount according to the actual value of the active current includes:

[0017] According to the formula Δf=-Kp 2 I q0 Calculate and determine the frequency compensation amount;

[0018] Among them, Δf is the frequency compensation; Kp 2 is the preset second proportional coefficient; I q0 is the actual value of active current.

[0019] In some embodiments, the step of obtaining the actual value of reactive current and the actual value of active current of the motor includes:

[0020] Clark transformation and Park transformation are performed on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current.

[0021] In some embodiments, before the step of performing Clark transformation and Park transformation on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current, the step includes:

[0022] The three-phase current of the motor stator is measured using Hall sensors.

[0023] In a second aspect, a permanent magnet synchronous motor VF control device is provided, comprising:

[0024] An acquisition unit, the acquisition unit is used to acquire the actual value of reactive current and the actual value of active current of the motor;

[0025] A determination unit, the determination unit is used to determine a low-frequency voltage compensation amount according to an actual value of a reactive current and a preset reactive current given value, and to determine a frequency compensation amount according to an actual value of an active current;

[0026] A control unit is used to compensate the output voltage according to the low-frequency voltage compensation amount, and to compensate the output frequency according to the frequency compensation amount, and then control the operation of the motor according to the compensated output voltage and the compensated output frequency.

[0027] In a third aspect, a computer device is provided, comprising: a memory and a processor, wherein the memory stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the aforementioned permanent magnet synchronous motor VF control method.

[0028] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions. When the computer instructions are executed by a computer, the computer executes the aforementioned permanent magnet synchronous motor VF control method.

[0029] The beneficial effects brought about by the technical solution provided by the present invention include:

[0030] The embodiment of the present invention provides a permanent magnet synchronous motor VF control method, device, equipment and readable storage medium. First, the actual value of the reactive current and the actual value of the active current of the motor are obtained; then the low-frequency voltage compensation amount is determined according to the actual value of the reactive current and the preset reactive current given value, and the frequency compensation amount is determined according to the actual value of the active current; finally, the output voltage is compensated according to the low-frequency voltage compensation amount, and the output frequency is compensated according to the frequency compensation amount, and the motor operation is controlled according to the compensated output voltage and the compensated output frequency. On the one hand, the present invention compensates the output voltage by the actual value of the reactive current during low-frequency operation to improve the low-frequency operation stability and starting load capacity of the motor. On the other hand, the output frequency is compensated by the actual value of the active current to keep the motor flux stable under no-load or light-load conditions, and provide sufficient terminal voltage under heavy load conditions to ensure the smooth operation of the motor. When the present invention controls the operation of different motors, it is not necessary to repeatedly adjust the coefficient of the high-pass filter, and it has strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A schematic flow chart of a VF control method for a permanent magnet synchronous motor provided by an embodiment of the present invention;

[0033] Figure 2 Another schematic flow chart of a VF control method for a permanent magnet synchronous motor provided by an embodiment of the present invention;

[0034] Figure 3 A schematic structural diagram of a VF control device for a permanent magnet synchronous motor provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the structure of a computer device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The embodiment of the present invention provides a permanent magnet synchronous motor VF control method, which can solve the technical problem that the existing permanent magnet synchronous motor VF control method needs to repeatedly adjust the high-pass filter coefficient when controlling different motor operations and has poor adaptability.

[0038] See also Figure 1 As shown, an embodiment of the present invention provides a permanent magnet synchronous motor VF control method, comprising the following steps:

[0039] Step S10, obtaining the actual value of the reactive current and the actual value of the active current of the motor.

[0040] Specifically, see Figure 2 As shown, the step of obtaining the actual value of the reactive current and the actual value of the active current of the motor includes:

[0041] The three-phase current I of the motor stator a ,I b ,I c Perform Clark transformation and Park transformation to obtain the actual value of reactive current I d0 and the actual value of active current I q0 Clark transformation and Park transformation are used to obtain the actual value of reactive current and the actual value of active current. The results are accurate and reliable, which is convenient for subsequent motor control.

[0042] Step S20, determining a low-frequency voltage compensation amount according to the actual value of the reactive current and a preset reactive current given value, and determining a frequency compensation amount according to the actual value of the active current.

[0043] Specifically, the step of determining the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, and determining the frequency compensation amount according to the actual value of the active current includes:

[0044] According to the formula ΔV=Kp 1 ·(I d1 -I d0 ) calculates and determines the low-frequency voltage compensation. Where ΔV is the low-frequency voltage compensation; Kp 1 is the preset first proportionality coefficient; I d1 is the preset reactive current given value; I d0 is the actual value of reactive current.

[0045] According to the formula Δf=-Kp 2 I q0 Calculate and determine the frequency compensation amount. Where Δf is the frequency compensation amount; Kp 2 is the preset second proportional coefficient; I q0 is the actual value of active current.

[0046] Step S30, compensating the output voltage according to the low-frequency voltage compensation amount, and compensating the output frequency according to the frequency compensation amount, and then controlling the motor operation according to the compensated output voltage and the compensated output frequency.

[0047] Specifically, see Figure 2 As shown, the low-frequency voltage compensation amount ΔV is superimposed on the output voltage, and the frequency compensation amount Δf is superimposed on the output frequency, and the motor operation is controlled according to the compensated output voltage Vout and the compensated output frequency fout.

[0048] Taking a permanent magnet synchronous motor as an example, the working principle of the embodiment of the present invention is as follows:

[0049] The permanent magnet synchronous motor has a stator coil impedance, which provides a three-phase AC voltage U to the motor. s When, according to the formula U s =R s I s +L·di / dt+E mf , R s is the stator resistance, I s is the stator phase current, L is the stator phase inductance, E mf is the induced electromotive force of the stator winding, part of which will drop on the stator impedance. However, when the motor is at low frequency, the terminal voltage U s The stator resistance voltage drop is relatively small, so it is necessary to compensate for the stator resistance voltage drop. When the motor is running at high frequency, the motor back EMF is much higher than the stator resistance voltage drop, so the stator resistance voltage drop is usually ignored at high frequency. In addition, according to the formula T e =1.5N p ·Φ·I q , T e is the electromagnetic torque of the motor, N p is the number of motor poles, Φ is the flux linkage, I q For torque current, enhancing the magnetic field can improve the low-frequency electromagnetic torque of the motor, so it can be concluded that increasing the excitation current can improve the low-frequency load capacity of the motor.

[0050] Under certain speed conditions, the active current and electromagnetic torque of the permanent magnet synchronous motor are positively correlated. The greater the motor load, the greater the active current required. Similarly, when the motor is unloaded or lightly loaded, the torque pulsation of the motor fluctuates randomly, and the magnitude of the torque fluctuation is reflected in the magnitude of the active current. The change in active current caused by this torque pulsation is equivalent to the change in active current caused by the change in the motor load. According to the formula U s =R s I s +L·di / dt+E mf It can be seen that the larger the active current, the greater the stator phase current I sThe larger the motor terminal voltage U s It also needs to be larger to ensure stable operation of the motor. Then it can be concluded that when the load changes or the no-load torque pulsation does not adjust the output voltage at a certain speed, the adjustment method of adjusting the stator operating frequency can be equivalent to adjusting the output voltage without changing the stator operating frequency, so as to achieve stable operation of the permanent magnet synchronous motor VF control.

[0051] The VF control method of the permanent magnet synchronous motor in the embodiment of the present invention first obtains the actual value of the reactive current and the actual value of the active current of the motor; then determines the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, and determines the frequency compensation amount according to the actual value of the active current; finally, compensates the output voltage according to the low-frequency voltage compensation amount, and compensates the output frequency according to the frequency compensation amount, and then controls the operation of the motor according to the compensated output voltage and the compensated output frequency. On the one hand, the present invention compensates the output voltage by the actual value of the reactive current during low-frequency operation to improve the low-frequency operation stability and starting load capacity of the motor; on the other hand, it compensates the output frequency by the actual value of the active current, keeps the motor flux stable under no-load or light-load conditions, and provides sufficient terminal voltage under heavy-load conditions to ensure smooth operation of the motor. When the present invention controls the operation of different motors, it is not necessary to repeatedly adjust the coefficient of the high-pass filter, and has strong adaptability.

[0052] As an optional implementation, in an embodiment of the invention, the step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency includes:

[0053] When the motor is running at low frequency, the low-frequency voltage compensation is superimposed on the output voltage. When the motor operating frequency gradually increases, the low-frequency voltage compensation is linearly reduced to zero according to the motor operating frequency. The load capacity is increased at low frequency, and the low-frequency voltage compensation is withdrawn when entering medium and high frequencies, thereby improving the motor efficiency.

[0054] As an optional implementation, in an embodiment of the invention, the step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency, further includes:

[0055] The frequency compensation amount is superimposed on the output frequency and the frequency compensation amount is limited to prevent interference and ensure stable control.

[0056] As an optional implementation, in an embodiment of the invention, before the step of performing Clark transformation and Park transformation on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current, the step includes:

[0057] The three-phase current of the motor stator is measured by using Hall sensor. The Hall sensor has fast response time, low temperature drift, high precision, small size, wide frequency band, strong anti-interference ability and strong overload capacity. The Hall sensor can accurately measure the three-phase current of the motor stator.

[0058] See also Figure 3 As shown, an embodiment of the present invention further provides a permanent magnet synchronous motor VF control device, including: an acquisition unit, a determination unit and a control unit.

[0059] The acquisition unit is used to acquire the reactive current actual value and the active current actual value of the motor.

[0060] The determination unit is used to determine the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, and to determine the frequency compensation amount according to the actual value of the active current.

[0061] The control unit is used to compensate the output voltage according to the low-frequency voltage compensation amount, and to compensate the output frequency according to the frequency compensation amount, and then to control the operation of the motor according to the compensated output voltage and the compensated output frequency.

[0062] The permanent magnet synchronous motor VF control device in the embodiment of the present invention first obtains the actual value of the reactive current and the actual value of the active current of the motor; then determines the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, and determines the frequency compensation amount according to the actual value of the active current; finally, compensates the output voltage according to the low-frequency voltage compensation amount, and compensates the output frequency according to the frequency compensation amount, and then controls the operation of the motor according to the compensated output voltage and the compensated output frequency. On the one hand, the present invention compensates the output voltage by the actual value of the reactive current during low-frequency operation to improve the low-frequency operation stability and starting load capacity of the motor; on the other hand, it compensates the output frequency by the actual value of the active current, keeps the motor flux stable under no-load or light-load conditions, and provides sufficient terminal voltage under heavy-load conditions to ensure smooth operation of the motor. When the present invention controls the operation of different motors, it is not necessary to repeatedly adjust the coefficient of the high-pass filter, and has strong adaptability.

[0063] It should be noted that those skilled in the art can clearly understand that, for the convenience and simplicity of description, the specific working process of the above-described device and each unit can refer to the corresponding process in the aforementioned permanent magnet synchronous motor VF control method embodiment, and will not be repeated here.

[0064] The permanent magnet synchronous motor VF control device provided in the above embodiment can be implemented in the form of a computer program. The computer program can be used in Figure 4 Runs on the computer device shown.

[0065] An embodiment of the present invention also provides a computer device, comprising: a memory, a processor and a network interface connected via a system bus, wherein at least one instruction is stored in the memory, and at least one instruction is loaded and executed by the processor to implement all or part of the steps of the aforementioned permanent magnet synchronous motor VF control method.

[0066] The network interface is used for network communication, such as sending assigned tasks, etc. Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0067] The processor may be a CPU, or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, etc. The processor is the control center of the computer device, and uses various interfaces and lines to connect various parts of the entire computer device.

[0068] The memory can be used to store computer programs and / or modules. The processor realizes various functions of the computer device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a video playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as video data, image data, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device or other volatile solid-state storage device.

[0069] In one embodiment, the processor is used to run a computer program stored in the memory to implement the following steps:

[0070] Step S10, obtaining the actual value of the reactive current and the actual value of the active current of the motor.

[0071] Step S20, determining a low-frequency voltage compensation amount according to the actual value of the reactive current and a preset reactive current given value, and determining a frequency compensation amount according to the actual value of the active current.

[0072] Step S30, compensating the output voltage according to the low-frequency voltage compensation amount, and compensating the output frequency according to the frequency compensation amount, and then controlling the motor operation according to the compensated output voltage and the compensated output frequency.

[0073] As an optional implementation, in an embodiment of the invention, the step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency includes:

[0074] When the motor is running at low frequency, the low frequency voltage compensation amount is superimposed on the output voltage. When the motor operating frequency gradually increases, the low frequency voltage compensation amount is linearly reduced to zero according to the motor operating frequency.

[0075] As an optional implementation, in an embodiment of the invention, the step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency, further includes:

[0076] The frequency compensation amount is superimposed on the output frequency and the frequency compensation amount is limited.

[0077] As an optional implementation, in an embodiment of the invention, the step of determining the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value includes:

[0078] According to the formula ΔV=Kp 1 ·(I d1 -I d0 ) calculating and determining the low frequency voltage compensation amount;

[0079] Among them, ΔV is the low-frequency voltage compensation; Kp 1 is the preset first proportionality coefficient; I d1 is the preset reactive current given value; I d0 is the actual value of reactive current.

[0080] As an optional implementation, in an embodiment of the invention, the step of determining the frequency compensation amount according to the actual value of the active current includes:

[0081] According to the formula Δf=-Kp 2 I q0Calculate and determine the frequency compensation amount;

[0082] Among them, Δf is the frequency compensation; Kp 2 is the preset second proportional coefficient; I q0 is the actual value of active current.

[0083] As an optional implementation, in an embodiment of the invention, the step of obtaining the actual value of the reactive current and the actual value of the active current of the motor includes:

[0084] Clark transformation and Park transformation are performed on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current.

[0085] As an optional implementation, in an embodiment of the invention, before the step of performing Clark transformation and Park transformation on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current, the step includes:

[0086] The three-phase current of the motor stator is measured using Hall sensors.

[0087] The embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed, all or part of the steps of the aforementioned permanent magnet synchronous motor VF control method are implemented.

[0088] The embodiment of the present invention implements all or part of the aforementioned processes, and can also be completed by instructing related hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of each of the above methods can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electric carrier signals and telecommunication signals.

[0089] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, servers 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 and optical storage, etc.) containing computer-usable program codes.

[0090] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0091] The serial numbers in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0092] 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 process in the flowchart. 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.

[0093] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features invented herein.

Claims

1. A permanent magnet synchronous motor VF control method, characterized in that: The following steps are involved: Get the actual value of reactive current and active current of the motor; Determine the low-frequency voltage compensation amount according to the actual value of reactive current and the preset reactive current given value, and determine the frequency compensation amount according to the actual value of active current; The output voltage is compensated according to the low-frequency voltage compensation amount, and the output frequency is compensated according to the frequency compensation amount, and then the motor operation is controlled according to the compensated output voltage and the compensated output frequency; The step of determining the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value comprises: According to the formula ΔV=Kp1·(I d1 -I d0 ) calculating and determining the low frequency voltage compensation amount; Wherein, ΔV is the low-frequency voltage compensation amount; Kp1 is the preset first proportional coefficient; I d1 is the preset reactive current given value; I d0 is the actual value of reactive current; The step of determining the frequency compensation amount according to the actual value of the active current comprises: According to the formula Δf=-Kp2·I q0 Calculate and determine the frequency compensation amount; Wherein, Δf is the frequency compensation amount; Kp2 is the preset second proportional coefficient; I q0 is the actual value of active current.

2. The permanent magnet synchronous motor VF control method according to claim 1, characterized in that: The steps of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency include: When the motor is running at low frequency, the low frequency voltage compensation amount is superimposed on the output voltage. When the motor operating frequency gradually increases, the low frequency voltage compensation amount is linearly reduced to zero according to the motor operating frequency.

3. The permanent magnet synchronous motor VF control method according to claim 1, characterized in that: The step of compensating the output voltage according to the low-frequency voltage compensation amount, compensating the output frequency according to the frequency compensation amount, and then controlling the operation of the motor according to the compensated output voltage and the compensated output frequency also includes: The frequency compensation amount is superimposed on the output frequency and the frequency compensation amount is limited.

4. The permanent magnet synchronous motor VF control method according to claim 1, characterized in that: The step of obtaining the actual value of the reactive current and the actual value of the active current of the motor comprises: Clark transformation and Park transformation are performed on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current.

5. The permanent magnet synchronous motor VF control method according to claim 4, characterized in that: Before the step of performing Clark transformation and Park transformation on the three-phase current of the motor stator to obtain the actual value of the reactive current and the actual value of the active current, the step includes: The three-phase current of the motor stator is measured using Hall sensors.

6. A permanent magnet synchronous motor VF control device, characterized in that: include: An acquisition unit, the acquisition unit is used to acquire the actual value of reactive current and the actual value of active current of the motor; A determination unit, the determination unit is used to determine a low-frequency voltage compensation amount according to an actual value of a reactive current and a preset reactive current given value, and to determine a frequency compensation amount according to an actual value of an active current; A control unit, the control unit is used to compensate the output voltage according to the low-frequency voltage compensation amount, and to compensate the output frequency according to the frequency compensation amount, and then control the operation of the motor according to the compensated output voltage and the compensated output frequency; The determining unit is used to determine the low-frequency voltage compensation amount according to the actual value of the reactive current and the preset reactive current given value, including: According to the formula ΔV=Kp1·(I d1 -I d0 ) calculating and determining the low frequency voltage compensation amount; Wherein, ΔV is the low-frequency voltage compensation amount; Kp1 is the preset first proportional coefficient; I d1 is the preset reactive current given value; I d0 is the actual value of reactive current; The determining unit is used to determine the frequency compensation amount according to the actual value of the active current, including: According to the formula Δf=-Kp2·I q0 Calculate and determine the frequency compensation amount; Wherein, Δf is the frequency compensation amount; Kp2 is the preset second proportional coefficient; I q0 is the actual value of active current.

7. A computer device, characterized in that: include: A memory and a processor, wherein at least one instruction is stored in the memory, and the at least one instruction is loaded and executed by the processor to implement the permanent magnet synchronous motor VF control method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a computer, the computer executes the permanent magnet synchronous motor VF control method according to any one of claims 1 to 5.

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