Control method for switching open loop to closed loop of permanent magnet synchronous motor and computer equipment

Abstract

The invention belongs to the technical field of motor control, and discloses a control method for switching an open loop to a closed loop of a permanent magnet synchronous motor, which is used for switching the permanent magnet synchronous motor from speed loop open-loop operation to rotating speed current double-closed-loop operation. Calculating an included angle delta between the shafting of the virtual synchronous rotating coordinate system dvirqvir and the shafting of the real rotor synchronous coordinate system dq; and then instantaneous switching of a command value of a current regulator, instantaneous switching of a current space voltage vector, switching of an angle variable used by coordinate transformation, initialization of a previous value of a low-pass filter, initialization of an integral term of the current regulator and initialization of an integral term of a speed regulator are executed in sequence, and open-loop switching and closed-loop switching of the permanent magnet synchronous motor are completed. According to the invention, the switching time is effectively shortened, and the switching stability and universality are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of PMSM (permanent magnet synchronous motor) motor control, and particularly relates to a control method for open-loop to closed-loop switching of sensorless FOC (field-oriented control, also known as vector control) of a PMSM motor. Background Art

[0002] PMSM motors have been widely used in products in various industries, such as fans, water pumps, air-conditioning compressors, machine tools, textile machinery, etc. PMSM motors are small in size and high in efficiency, but they are a complex non-linear system in themselves and have relatively high requirements for drive technology.

[0003] The control algorithm of PMSM motors generally adopts the vector control algorithm, that is, the FOC control algorithm. The vector control algorithm consists of modules such as coordinate transformation, current sampling and reconstruction, position estimator, speed loop regulator, current loop regulator, space vector modulation (SVPWM), etc. At present, most position estimators cannot accurately estimate the position of the motor rotor under the conditions of zero speed and ultra-low speed of the PMSM motor, resulting in the inability of the motor to directly start in a closed loop from a stationary state.

[0004] Currently, the industry mostly uses the traditional three-stage starting method for PMSM motor starting. That is, the motor is started through three stages: the rotor initial position positioning stage, the I / F (current frequency ratio) open-loop operation stage, and the speed-current double closed-loop operation stage.

[0005] In the first step, the rotor initial position positioning stage, the initial position angle of the rotor is found through a specific algorithm, or a fixed current vector is directly given through the current loop regulator to attract the rotor to the specified initial position angle.

[0006] In the second step, the open-loop strong drag stage, the speed loop is open-loop and the current loop is closed-loop. A fixed current vector amplitude is given, and the angles used in Park transformation and inverse Park transformation are obtained by integrating the command speed, and the initial value of the integration is the initial position angle obtained in the first step. At this time, a rotating magnetic field will be generated to force the rotor to rotate following the given rotating magnetic field. When the rotor speed reaches a certain speed, the position estimator estimates the accurate position information of the rotor (including speed and position angle), switches from open-loop to closed-loop, and then enters the third step.

[0007] In the third step, the speed-current double closed-loop stage, the current loop is the inner loop and the speed loop is the outer loop. The angle and speed information estimated by the position estimator are sent to the Park transformation and inverse Park transformation modules and the speed loop for use, and the speed loop regulator works.

[0008] When the existing starting method switches from open-loop to closed-loop, when the angle used in the Park transformation and the inverse Park transformation changes from the open-loop given angle to the angle estimated by the position estimator, if the algorithm does not handle this, current oscillation is very likely to occur during the switching process, resulting in a sudden change in current during the switching process. In severe cases, it may lead to motor startup failure or even demagnetization of the rotor permanent magnet.

[0009] Existing technologies such as Chinese patents with patent publication numbers CN114598222A and CN116582048A, during the open-loop to closed-loop process, adopt a variable-weight weighted transition method. During the switching process, the angles used in the Park transformation and the inverse Park transformation are composed of the angle estimated by the position estimator and the open-loop given angle combined according to a certain weight. This method does not introduce a speed loop during the transition switching stage, and has poor anti-load disturbance ability. In the case of relatively large changes in the load torque, it is still prone to losing steps. Another example is the Chinese patent with patent publication number CN111193442A, which sets a transition time. During the transition time, the voltage amplitude is decreased. When the voltage amplitude decreases to be close to the voltage required by the current load, the switching is performed. This method needs to collect the voltage amplitude required by the current load, and different voltages need to be set for different loads, resulting in poor algorithm generality. Another example is the Chinese patent with patent publication number CN111080540B. During the switching stage, the given values of Id and Iq are adjusted according to the sine and cosine laws, and the switching is performed when the difference between the open-loop given angle and the angle estimated by the position estimator is very small. This method has a long adjustment time, and the angle difference generally cannot be zero, resulting in an impact during switching.

[0010] Therefore, how to effectively make the PMSM motor stably and seamlessly switch from the open-loop forced-dragging stage to the closed-loop operation stage is one of the most important problems to be solved in this field. Summary of the Invention

[0011] One of the purposes of the present invention is to provide a control method for open-loop to closed-loop switching of a permanent magnet synchronous motor, which shortens the switching time and improves the switching stability.

[0012] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0013] A control method for open-loop to closed-loop switching of a permanent magnet synchronous motor, used for the permanent magnet synchronous motor to switch from open-loop operation of the speed loop to double closed-loop operation of speed and current. The control method for open-loop to closed-loop switching of the permanent magnet synchronous motor includes:

[0014] When the motor speed reaches the speed switching point, calculate the angle δ between the d vir q vir axis of the virtual synchronous rotating coordinate system and the dq axis of the real rotor synchronous coordinate system;

[0015] Instantaneous switching of the current regulator command value: During the open-loop operation of the speed loop, d virThe command values of the shaft current are respectively projected onto the dq-axis system as the command values of the d-axis current and the q-axis current after instantaneous switching;

[0016] Instantaneous switching of the current space voltage vector: The current space voltage vector is switched within the d vir q vir axis system to obtain the d-axis component and the q-axis component within the dq-axis system; vir axis component and the q vir axis component are switched to within the dq-axis system to obtain the d-axis component and the q-axis component within the dq-axis system;

[0017] Switching of the angular variable used for coordinate transformation: The angles used for Park transformation and inverse Park transformation are switched to the rotor position angle output by the position estimator;

[0018] Initialization of the previous value of the low-pass filter for current reference: The previous value used by the d-axis low-pass filter is initialized to the d-axis component of the command value of the shaft current projected onto the dq-axis system during the open-loop operation of the speed loop, and the previous value used by the q-axis low-pass filter is initialized to the q-axis component of the command value of the shaft current projected onto the dq-axis system during the open-loop operation of the speed loop; vir axis current projected onto the d-axis component within the dq-axis system, and the previous value used by the q-axis low-pass filter is initialized to the d vir axis current projected onto the q-axis component within the dq-axis system;

[0019] Initialization of the integral term of the current regulator: The integral term of the d-axis current regulator is initialized to the d-axis component of the current space voltage vector switched to the dq-axis system, and the integral term of the q-axis current regulator is initialized to the q-axis component of the current space voltage vector switched to the dq-axis system;

[0020] Initialization of the integral term of the speed regulator: The integral term of the speed regulator is initialized to the q-axis component of the command value of the r-axis current projected onto the dq-axis system during the open-loop operation of the speed loop; vi axis current projected onto the q-axis component within the dq-axis system;

[0021] The open-loop to closed-loop conversion of the permanent magnet synchronous motor is completed.

[0022] The following also provides several optional methods, which are not additional limitations to the above overall solution, but are only further supplements or optimizations. Without technical or logical contradictions, each optional method can be combined separately with the above overall solution, or multiple optional methods can be combined with each other.

[0023] Preferably, for the open-loop operation of the speed loop, the following controls are as follows:

[0024] Let the angle between the d vir q vir axis system of the virtual synchronous rotating coordinate system and the αβ-axis system of the two-phase stationary coordinate system be angle obtained by integrating the commanded angular velocity with respect to time, and the initial value of the integration is the initial position angle obtained during the initial position positioning stage;

[0025] Set the angle used for Park transformation and inverse Park transformation to

[0026] d vir The commanded value of the d-axis current, Idcmd vir is set to the rated current of the motor and given through a low-pass filter. For q vir The commanded value of the q-axis current, Iqcmd vir is set to zero;

[0027] The current loop operates in a closed loop to control the starting and acceleration of the permanent magnet synchronous motor. Meanwhile, the position estimator starts to work and outputs the rotor position angle θ est and the rotor angular velocity ω est , where the included angle

[0028] Preferably, after the instantaneous switching of the commanded value of the current regulator, the initial value of the commanded value of the d-axis current is Idcmd vir × cosδ, where Idcmd vir is the commanded value of the d-axis current during the open-loop operation of the speed loop, and then smoothly transitions to 0 through a low-pass filter. The initial value of the commanded value of the q-axis current is Idcmd vir × sinδ, and then smoothly transitions to the output of the speed regulator through a low-pass filter. vir × sinδ, and then smoothly transitions to the output of the speed regulator through a low-pass filter.

[0029] Preferably, when the current space voltage vector is instantaneously switched:

[0030] Take the d-axis component of the current space voltage vector in the d vir q vir axis system as Vd vir , and the q-axis component in the d vir q vir axis system as Vq vir ; vir ; vir ;

[0031] Calculate the d-axis component of the current space voltage vector after switching to the dq axis system as follows:

[0032] Vd = Vd vir × cosδ - Vq vir × sinδ

[0033] Calculate the q-axis component of the current space voltage vector after switching to the dq axis system as follows:

[0034] Vq = Vd vir × sinδ + Vq vir × cosδ

[0035] Wherein, Vd is the d-axis component of the current space voltage vector switched to the dq-axis system, Vq is the q-axis component of the current space voltage vector switched to the dq-axis system, the output value of the d-axis current regulator is assigned to Vd, and the output value of the q-axis current regulator is assigned to Vq.

[0036] Preferably, the current regulator adopts a PI controller.

[0037] Preferably, the speed regulator adopts a PI controller.

[0038] For a control method of open-loop to closed-loop switching of a permanent magnet synchronous motor provided by the present invention, both the current vector and the voltage vector are switched from the virtual synchronous rotating coordinate system d vir q vir axis system to the dq-axis system of the real rotor synchronous coordinate system. This ensures the continuity of the current and voltage space vectors before and after switching, so current mutation will not occur. When carrying different loads, the angle difference δ between the two axis systems is different, but the same set of logic is used during switching. Therefore, the method adopted by the present invention is not affected by the magnitude of the load torque, and this method can be used for any form of load, and this method has good robustness. In addition, this method does not need to make the virtual synchronous rotating coordinate system and the real rotor synchronous coordinate system coincide as in the existing traditional strategies as much as possible. The switching is completed instantaneously without a transition time, so the switching time is short and can be completed within one carrier period.

[0039] The second object of the present invention is to provide a computer device, including a processor and a memory storing a number of computer instructions, and when the computer instructions are executed by the processor, the steps of the control method of open-loop to closed-loop switching of the permanent magnet synchronous motor are implemented. Description of the Drawings

[0040] Figure 1 It shows the application of the control method of open-loop to closed-loop switching of a permanent magnet synchronous motor of the present invention in the traditional three-stage starting method. The dashed box is the control method of open-loop to closed-loop switching of the permanent magnet synchronous motor of the present invention;

[0041] Figure 2 It is the I / F operating current vector diagram in the traditional three-stage starting method;

[0042] Figure 3 It is the flowchart of the control method of open-loop to closed-loop switching of a permanent magnet synchronous motor of the present invention;

[0043] Figure 4 It is the instantaneous switching schematic diagram of the ACR command value of the current regulator of the present invention;

[0044] Figure 5 It is the instantaneous switching schematic diagram of the current space voltage vector of the present invention;

[0045] Figure 6 This is the experimental effect diagram of a control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to the present invention. Specific embodiments

[0046] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention.

[0048] This embodiment provides a control method for open-loop to closed-loop switching of a permanent magnet synchronous motor. As Figure 1 shown, in the open-loop to closed-loop system of the FOC control algorithm of the permanent magnet synchronous motor, when the speed switching point is reached after I / F open-loop operation, the position estimator has converged. When the estimated rotational speed and rotor position by the estimator are close to the actual values, a switch is made, solving the technical problem of reliable switching of the FOC control algorithm from open-loop to closed-loop. This can make the open-loop to closed-loop switching smoother, with no current impact. Most importantly, it is applicable to switching under no-load, light-load, and heavy-load conditions without parameter adjustment and has good robustness.

[0049] In the traditional three-stage starting method, after the rotor initial position positioning stage, it enters the speed loop open-loop operation stage. As Figure 2 shown, the angle between the established virtual synchronous rotating coordinate system d vir q vir axis system and the two-phase stationary coordinate system αβ axis system is angle obtained by integrating the command angular velocity with respect to time, and the initial value of the integration is the initial angle θ initial obtained in the initial position positioning stage, where the command angular velocity is set artificially and can be understood as the target speed of the motor operation, which is set and output through the speed setting module.

[0050] Set the angle used for Park transformation and inverse Park transformation as The command value Idcmd of the dvir axis current vir is set to the rated current of the motor and given through a low-pass filter to achieve the purpose of slow start. q vir The command value Iqcmd of the axis current virSet to zero.

[0051] The current loop operates in a closed loop to control the start and acceleration of the permanent magnet synchronous motor. At the same time, the position estimator starts to work and outputs the rotor position angle θ est and the rotor angular velocity ω est .

[0052] When the motor speed reaches the speed switching point, the angle between the virtual synchronous rotating coordinate system d vir q vir axis system and the real rotor synchronous coordinate system dq axis system is δ. According to calculation, within one carrier cycle, the motor "seamlessly" switches from open-loop I / F control to speed-current double closed-loop control. As Figure 3 shown, the work to be completed by the one-step switching method proposed in the present invention is detailed as follows:

[0053] (1) Instantaneous switching of the command value of the current regulator ACR: Project the command values of the d vir axis current during the open-loop operation of the speed loop onto the dq axis system respectively, as the command value of the d axis current and the command value of the q axis current after instantaneous switching. As Figure 4 shown, the command value of the d vir axis current Idcmd vir during the open-loop operation of the speed loop, the d axis component Idcmd in the dq axis system is Idcmd vir ×cosδ, that is, the initial value of the command value of the d axis current Idcmd is switched to Idcmd vir ×cosδ, and then smoothly transitions to 0 through a low-pass filter LPF; the command value of the d vir axis current Idcmd vir during the open-loop operation of the speed loop, the q axis component Iqcmd in the dq axis system is Idcmd vir ×sinδ, that is, the initial value of the command value of the q axis current Iqcmd is switched to Idcmd vir ×sinδ, and then smoothly transitions to the output of the speed regulator ASR through a low-pass filter LPF.

[0054] (2) Instantaneous switching of the current space voltage vector: Switch the d vir q vir axis component and the q vir axis component of the current space voltage vector within the d vir axis system to the dq axis system to obtain the d axis component and the q axis component within the dq axis system.

[0055] As Figure 5 shown, take the current space voltage vector Vs in the virtual synchronous rotating coordinate system d vir q vir axis system, the d virThe d-axis component is Vd vir , in the d vir q vir axis system of the virtual synchronous rotating coordinate system vir The q-axis component is Vq vir .

[0056] The calculation of the d-axis component of the current space voltage vector Vs switched to the dq-axis system of the real rotor synchronous coordinate system is as follows:

[0057] Vd = Vd vir × cosδ - Vq vir × sinδ

[0058] The calculation of the q-axis component of the current space voltage vector Vs switched to the dq-axis system of the real rotor synchronous coordinate system is as follows:

[0059] Vq = Vd vir × sinδ + Vq vir × cosδ

[0060] In the formula, Vd is the d-axis component of the current space voltage vector switched to the dq-axis system, Vq is the q-axis component of the current space voltage vector switched to the dq-axis system, the output value of the d-axis current regulator is assigned to Vd, and the output value of the q-axis current regulator is assigned to Vq.

[0061] (3) Switching of the angle variable used in the coordinate transformation: The angles used in the Park transformation and the inverse Park transformation are switched from to the rotor position angle θ output by the position estimator wst .

[0062] (4) Initialization of the previous value of the low-pass filter for the current command: The low-pass filter is used when giving the d-axis current command value Idcmd and the q-axis current command value Iqcmd. The previous value used by the d-axis low-pass filter is initialized to the projection of the d-axis current command value in the open-loop operation of the speed loop to the d-axis component in the dq-axis system, that is, Idcmd vir × cosδ, and the previous value used by the q-axis low-pass filter is initialized to the projection of the d-axis current command value in the open-loop operation of the speed loop to the q-axis component in the dq-axis system, that is, Idcmd vir × sinδ. vir axis current command value projected to the q-axis component in the dq-axis system, that is, Idcmd vir × sinδ.

[0063] (5) Initialization of the integral term of the current regulator ACR: The current regulator uses a PI controller. The integral term of the d-axis current regulator is initialized to the d-axis component of the current space voltage vector switched to the dq-axis system, that is, Vd, and the integral term of the q-axis current regulator is initialized to the q-axis component of the current space voltage vector switched to the dq-axis system, that is, Vq.

[0064] (6) Initialization of the integral term of the speed regulator ASR: The speed regulator adopts a PI controller. The integral term of the speed regulator is initialized as d during the open-loop operation of the speed loop vir The command value of the shaft current is projected onto the q-axis component in the dq-axis system, i.e., Idcmd vir ×sinδ.

[0065] Complete the open-loop to closed-loop switching of the permanent magnet synchronous motor. After switching, both the current vector and the voltage vector are switched from the virtual synchronous rotating coordinate system d vir q vir axis system to the real rotor synchronous coordinate system dq axis system. This ensures the continuity of the current and voltage space vectors before and after switching, so there will be no current mutation. When driving different loads, the angle difference δ between the two axis systems is different, but the same set of logic is used during switching. Therefore, the method adopted in the present invention is not affected by the magnitude of the load torque, and any form of load can adopt this method, and this method has good robustness. In addition, this method does not need to make the virtual synchronous rotating coordinate system and the real rotor synchronous coordinate system coincide as hard as the existing traditional strategies. The switching is completed instantaneously without a transition time, so the switching time is short and can be completed within one carrier cycle.

[0066] The present invention has been programmed and implemented on an MCU (microcontroller), and this MCU is used to mass-produce a certain model of motor driver. This driver drives a permanent magnet synchronous motor. The motor drives a load with 100% torque and starts from zero speed. After passing through the initial position positioning stage of the initial rotor and open-loop operation, it switches to speed-current double closed-loop operation at 10% of the rated speed of the motor. The switching effect is as Figure 6 shown. It can be seen that when switching from the open-loop operation of the speed loop to the speed-current double closed-loop operation, the current hardly mutates at all, indicating that the switching method of the present invention has high stability and short switching time.

[0067] In another embodiment, the present invention also provides a computer device, including a processor and a memory storing a number of computer instructions. When the computer instructions are executed by the processor, the steps of the control method for the open-loop to closed-loop switching of the permanent magnet synchronous motor are implemented.

[0068] The memory and the processor are directly or indirectly electrically connected to achieve data transmission or interaction. For example, these components can be electrically connected to each other through one or more communication buses or signal lines. The memory stores a computer program that can run on the processor. The processor runs the computer program stored in the memory to implement the method in the embodiments of the present invention.

[0069] Among them, the memory may be, but is not limited to, a Random Access Memory (RAM), a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable Programmable Read-Only Memory (EPROM), an Electric Erasable Programmable Read-Only Memory (EEPROM), etc. Among them, the memory is used to store a program, and the processor executes the program after receiving an execution instruction.

[0070] The processor may be an integrated circuit chip with data processing capabilities. The above-mentioned processor may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc. It can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of the present invention. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0071] The technical features of the above-mentioned embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0072] The above-mentioned embodiments only express several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be understood as a limitation to the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A control method for switching a permanent magnet synchronous motor from open - loop operation of the speed loop to closed - loop operation of speed and current, characterized in that, The control method for open-loop to closed-loop switching of the permanent magnet synchronous motor includes: When the motor speed reaches the speed switching point, calculate the angle δ between the virtual synchronous rotating coordinate system d vir q vir axis system and the dq axis system of the real rotor synchronous coordinate system; Instantaneous switching of the command value of the current regulator: When the speed loop operates in open loop, project the command value of the shaft current onto the dq-axis system respectively as the command value of the d-axis current and the command value of the q-axis current after instantaneous switching; vir ​ Instantaneous switching of the current space voltage vector: Switch the current space voltage vector in the d vir q vir axis system to obtain the d vir axis component and the q vir axis component in the dq axis system, and obtain the d-axis component and the q-axis component in the dq axis system; Switching of the angular variable used in coordinate transformation: The angle used in Park transformation and inverse Park transformation is switched to the rotor position angle output by the position estimator; Initialization of the previous value of the low-pass filter for current reference: The previous value used by the d-axis low-pass filter is initialized to the d-axis current command value projected into the dq-axis system during open-loop operation of the speed loop. vir The previous value used by the q-axis low-pass filter is initialized to the q-axis component of the d-axis current command value projected into the dq-axis system during open-loop operation of the speed loop. vir The previous value used by the q-axis low-pass filter is initialized to the q-axis component of the d-axis current command value projected into the dq-axis system. Initialization of the integral term of the current regulator: The integral term of the d-axis current regulator is initialized to the d-axis component of the current space voltage vector switched to the dq-axis system, and the integral term of the q-axis current regulator is initialized to the q-axis component of the current space voltage vector switched to the dq-axis system; Initialization of the speed regulator integral term: The speed regulator integral term is initialized to d during the open-loop operation of the speed loop vir The command value of the shaft current is projected onto the q-axis component in the dq-axis system; Complete the open-loop to closed-loop switching of the permanent magnet synchronous motor.

2. The control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to claim 1, wherein The speed loop operates in open loop, and the controls are as follows: Let the angle between the d vir q vir axis system of the virtual synchronous rotating coordinate system and the αβ axis system of the two-phase stationary coordinate system be the angle obtained by integrating the commanded angular velocity with respect to time, and the initial value of the integration is the initial position angle obtained in the initial position positioning stage; Set the angle used for Park transformation and inverse Park transformation as d vir Command value of shaft current Idcmd vir Is set to the rated current of the motor and given through a low-pass filter, q vir Command value of shaft current Iqcmd vir Is set to zero; The current loop operates in a closed loop to control the starting and acceleration of the permanent magnet synchronous motor. Meanwhile, the position estimator starts to work and outputs the rotor position angle θ est and the rotor angular velocity ω est , where the included angle 3. The control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to claim 1, wherein After the instantaneous switching of the command value of the current regulator, the initial value of the command value of the d-axis current is Idcmd vir ×cosδ, Idcmd vir is the command value of the d vir axis current during the open-loop operation of the speed loop, and then smoothly transitions to 0 through a low-pass filter. The initial value of the command value of the q-axis current is Idcmd vir ×sinδ, and then smoothly transitions to the output of the speed regulator through a low-pass filter.

4. The control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to claim 1, characterized in that, When the instantaneous switching of the current space voltage vector occurs: Obtain the d-component of the current space voltage vector in the vir q vir axis system as Vd vir , and the q-component of the current space voltage vector in the vir d vir q vir axis system as Vq vir ; vir ; Calculate the d-axis component of the current space voltage vector switched to the dq-axis system as follows: Vd = Vd vir × cosδ - Vq vir × sinδ Calculate the q-axis component of the current space voltage vector switched to the dq-axis system as follows: Vq = Vd vir ×sinδ + Vq vir ×cosδ Wherein, Vd is the d-axis component of the current space voltage vector switched to the dq-axis system, Vq is the q-axis component of the current space voltage vector switched to the dq-axis system, the output value of the d-axis current regulator is assigned to Vd, and the output value of the q-axis current regulator is assigned to Vq.

5. The control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to claim 1, wherein The current regulator uses a PI controller.

6. The control method for open-loop to closed-loop switching of a permanent magnet synchronous motor according to claim 1, wherein The speed regulator uses a PI controller.

7. A computer device, comprising a processor and a memory storing a number of computer instructions, characterized in that, When the computer instruction is executed by the processor, the steps of the control method for open-loop to closed-loop switching of the permanent magnet synchronous motor described in any one of claims 1 to 6 are implemented.

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