Permanent magnet synchronous motor simulation system and control method

Abstract

The invention provides a permanent magnet synchronous motor simulation system and a control method. The system comprises a first converter, a second converter, an impedance controller, a current non-feedback controller, a filter inductor, a current Hall sensor and a rotating speed loop controller. The first converter and the second converter are in three-phase connection through a filter inductor; the impedance controller is connected with a connecting branch of the first converter and the second converter, is connected with the current non-feedback controller, and is used for carrying out control processing on the acquired three-phase sampling voltage in combination with the current non-feedback controller and outputting a modulation voltage of the second converter; the current Hall sensor is arranged on the connecting branch; the rotating speed loop controller is connected with the first converter and the current Hall sensor, and is used for controlling and outputting modulation voltage according to the reference rotating speed and the collected three-phase current and transmitting the modulation voltage to the first converter. The application that the current waveform is not distorted when the motor simulation system runs at a high speed is realized, and the stability of the simulation system is effectively improved.

Description

Technical Field

[0001] The present application belongs to the technical field of power electronics and motor simulation systems, and in particular, relates to a permanent magnet synchronous motor simulation system and a control method. Background Art

[0002] High-Speed ​​Permanent Magnet Synchronous Motor (HSPMSM) is a highly efficient and energy-saving electric motor widely used in many industries. The working principle of HSPMSM is based on the law of electromagnetic induction. Its core component is a permanent magnet, usually a rare earth material (such as neodymium iron boron), which is used to generate a stable magnetic field. The rotor of the motor is composed of permanent magnets, and the stator is energized to generate a rotating magnetic field, so that the rotor rotates synchronously with the rotating magnetic field of the stator. Due to its good characteristics such as high power density, wide speed range, and low vibration and noise, it has been widely used in electric vehicles, aerospace, and wind power generation equipment. In these application scenarios, the complex and changeable working environment puts extremely strict requirements on the reliability of the entire system. Therefore, these power electronic equipment must verify their control functions and reliability performance before being put into operation.

[0003] In traditional test verification methods, in order to meet test requirements, actual permanent magnet synchronous motors and other complex mechanical components are needed. This test method based on actual motors has many inconveniences: the actual motors are large in size and expensive, and cannot be in working condition for a long time during the test; the energy consumption is high, which is a huge waste of electric energy and poses a great safety hazard; in the test of complex working conditions, there will be limitations on dynamic performance.

[0004] The existing technology can simulate various working conditions of real motors based on power electronics simulation technology. Although there has been preliminary research on the simulation system control of various motors and it has been applied in different fields, the traditional motor simulation system control method has limitations. For example, when the load or speed changes suddenly, the motor simulation system will become unstable, resulting in poor dynamic tracking performance and failure to successfully simulate all the characteristics of the real motor. Summary of the invention

[0005] The main purpose of the embodiments of the present invention is to provide a permanent magnet synchronous motor simulation system and control method, which solves the problem of current and speed oscillation in the motor simulation control system when running at high speed in the prior art, realizes the application of the motor simulation system without distortion of the current waveform when running at high speed, and effectively improves the stability of the simulation system.

[0006] In the first aspect, a permanent magnet synchronous motor simulation system is provided, which includes: a first converter, a second converter, an impedance controller, a current feedback-free controller, a filter inductor, a current Hall sensor and a speed loop controller; the first converter and the second converter are connected in three phases through a filter inductor; the impedance controller is connected to a connecting branch between the first converter and the second converter, and is connected to the current feedback-free controller, and is used to control and process the three-phase sampling voltage collected from the connecting branch in combination with the current feedback-free controller, and the output voltage is used as a modulation voltage of the second converter; the current Hall sensor is arranged on the connecting branch, and is used to collect three-phase current; the speed loop controller is connected to the first converter, and is used to control the output modulation voltage according to the input preset reference speed and the collected three-phase current and transmit it to the first converter.

[0007] In another possible implementation, the first converter adopts a vector control mode in which the d-axis component of the reference current of the permanent magnet synchronous motor is zero, and is set to a voltage type working mode.

[0008] In one possible implementation, the transfer function of the impedance controller is for: in, represents the Laplace transform domain, is the transfer function of the permanent magnet synchronous motor, is the stator resistance, is the stator inductance, is the transfer function of the filter inductor, is the filter inductor impedance, For the filter inductor.

[0009] In another possible implementation, the transfer function of the permanent magnet synchronous motor simulation system is for: in, is the transfer function of the speed loop controller, is the transfer function of the impedance controller, is the angular velocity of the preset frequency.

[0010] In another possible implementation, the permanent magnet synchronous motor simulation system also includes: a coordinate transformer, which is connected between the current Hall sensor and the speed loop controller and is used to perform coordinate transformation on the three-phase current collected by the current Hall sensor and output it to the speed loop controller.

[0011] In the second aspect, a control method for a permanent magnet synchronous motor simulation system is provided, including: inputting a preset reference speed into a speed loop controller, and controlling the first converter to operate in a voltage-type operating mode; using an impedance controller to output a voltage according to a collected three-phase sampling voltage as a modulation voltage of the second converter, and combining with a current feedback-free controller to control the output feedback current; obtaining the mechanical angular velocity of the permanent magnet synchronous motor according to the feedback current in combination with a PMSM model; applying a speed loop controller to obtain a reference current according to a reference speed and a mechanical angular velocity in combination with proportional and integral processing of the speed loop, and combining the reference current and the collected three-phase current to control the output modulation voltage of the permanent magnet synchronous motor, which is input to the first converter.

[0012] In another possible implementation, inputting a preset reference speed into the speed loop controller includes: setting an initial reference speed; and controlling the preset reference speed to increase from the initial reference speed to a target speed.

[0013] In another possible implementation, inputting a preset reference speed into the speed loop controller also includes: determining an initial value of the load torque of the motor, and controlling the load torque to step from the initial value to a preset torque at a preset time point.

[0014] In another possible implementation, an impedance controller is used to output a voltage based on the collected three-phase sampled voltage as a modulation voltage of the second converter, and is combined with a current no-feedback controller to control the output feedback current, including: inputting the collected three-phase sampled voltage into the impedance controller, and using the voltage output after proportional and integral processing by the impedance controller as the modulation voltage of the second converter; and applying a current no-feedback controller based on the voltage output by the impedance controller in combination with filter inductance processing to output the feedback current.

[0015] In another possible implementation, a speed loop controller is used to obtain a reference current based on a reference speed and a mechanical angular velocity in combination with proportional and integral processing of the speed loop, and the reference current and the collected three-phase current are combined to control the output modulation voltage of the permanent magnet synchronous motor, including: using a speed loop controller to calculate the difference between the reference speed and the mechanical angular velocity; controlling the difference to obtain a reference current after proportional and integral processing of the speed loop; subtracting the difference from the collected three-phase current after a sampling delay period, and outputting the modulation voltage of the permanent magnet synchronous motor after proportional and integral processing of the current loop. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in describing the embodiments of the present application.

[0017] Figure 1 A schematic diagram of the structure of a permanent magnet synchronous motor simulation system provided by an embodiment of the present invention; Figure 2 A schematic diagram of reference voltage and output current of a first converter and a second converter in an embodiment of the present invention; Figure 3 This is the control block diagram of the traditional motor simulation system; Figure 4 is a control block diagram of a permanent magnet synchronous motor simulation system in an embodiment of the present invention; Figure 5 is a Bode diagram comparing the current feedback-free control transfer function in the embodiment of the present invention with the real motor and current closed-loop control; Figure 6 A schematic diagram of signal flow under the dq axis in a permanent magnet synchronous motor simulation system provided by an embodiment of the present invention; Figure 7 A schematic diagram comparing the current waveforms of a permanent magnet synchronous motor simulation system and an actual motor provided by an embodiment of the present invention, wherein (a) is an actual motor and (b) is a permanent magnet synchronous motor simulation system; Figure 8 A schematic diagram comparing the speed and torque waveforms of a permanent magnet synchronous motor simulation system and an actual motor provided by an embodiment of the present invention, wherein (a) is an actual motor and (b) is a permanent magnet synchronous motor simulation system; Fig. 9 A flowchart of a control method for a permanent magnet synchronous motor simulation system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present invention.

[0019] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, modules and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, modules, components and / or groups thereof. It should be understood that when we refer to a module as being "connected" or "coupled" to another module, it may be directly connected or coupled to the other modules, or there may be intermediate modules. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any modules and all combinations of one or more associated listed items.

[0020] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation method of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0021] The technical solution of the present application and how to solve the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0022] Figure 1 A schematic diagram of the structure of a permanent magnet synchronous motor simulation system provided by an embodiment of the present invention. Figure 1 The permanent magnet synchronous motor simulation system includes: a first converter, a second converter, an impedance controller, a current feedback-free controller, a filter inductor, a current Hall sensor and a speed loop controller. The first converter and the second converter are connected in three phases through the filter inductor. The impedance controller is connected to the connecting branch of the first converter and the second converter, and is connected to the current feedback-free controller, and is used to control and process the three-phase sampling voltage collected from the connecting branch in combination with the current feedback-free controller, and the output voltage is used as the modulation voltage of the second converter. The current Hall sensor is arranged on the connecting branch for collecting three-phase current. The speed loop controller is connected to the first converter, and is used to control the output modulation voltage according to the input preset reference speed and the collected three-phase current and transmit it to the first converter.

[0023] This application selects permanent magnet synchronous motor (PMSM) as the main research object. The main parameters are shown in Table 1.

[0024] Table 1 PMSM key parameters Two three-phase converters, namely the first converter and the second converter, are connected through a filter inductor. The first converter is connected to a DC power source through a fuse. If a short-circuit current exists due to an abnormal situation during operation, the fuse disconnects the two converters from the DC power source to protect the entire system.

[0025] The control of the permanent magnet synchronous motor simulation system includes three parts: three-phase sampling voltage, current, impedance regulation control and current non-feedback control. As the input of the impedance controller, the output of the impedance controller is used as the input of the current non-feedback control link, and finally the output As the modulation voltage of the second converter. The driving principle of the first converter is similar to the above. First, a uniform rising reference speed is given. As the input of the speed loop control, the first converter then adopts The vector control method is used, and it is in the voltage type working mode. The three-phase current collected by the Hall element is fed back to the first converter through coordinate transformation, and finally output As the modulation voltage of the first converter. According to the existing data, in the frequency domain model, the terminal voltage of the permanent magnet synchronous motor is Axis and The axis components can be expressed as: in, , The stator voltage is Axis component, , The stator current is Axis component, is the stator resistance, is the electrical angular velocity, , They are Shaft inductance component, is the permanent magnet flux.

[0026] The electromagnetic torque equation of PMSM can be written as: For surface mounted PMSM, , then the electromagnetic torque equation can be further transformed into: The mechanical equation of motion can be written as: in, is the electromagnetic torque, is the moment of inertia, is the damping coefficient, is the load torque.

[0027] In PMSM, due to the difference in pole pairs, the mechanical angle and electrical angle have the following multiple relationship: in, is the mechanical angular velocity of the motor (rad / s), is the pole pair number, is the motor speed (r / min), is the electrical angle of the motor rotor (rad).

[0028] The permanent magnet synchronous motor simulation system also includes: a coordinate transformer, which is connected between the current Hall sensor and the speed loop controller and is used to perform coordinate transformation on the three-phase current collected by the current Hall sensor and output the result to the speed loop controller.

[0029] The output of the first converter phase leg branch and the corresponding output of the second converter phase leg branch are connected through an inductor coil, and the filter inductors are not connected to each other. The first converter adopts the reference current of the permanent magnet synchronous motor. d The axis component is zero, that is , vector control mode, and set to voltage type working mode. Output current The output voltage between the first converter and the second converter The difference is generated. Figure 2 As shown, the output current is applied to the inductor. This means that the voltage is applied to the inductor in a short time. Therefore, in order to make the output current stable, an inductor with a smaller inductance value is sufficient to meet the requirements of the load inductance of the device. The transfer function of the permanent magnet synchronous motor itself is determined by its stator itself and can be expressed as: represents the Laplace transform domain.

[0030] Traditional motor analog control methods such as Figure 3 As shown, there is still a current closed loop inside the second converter, and this current closed loop will affect the high-frequency speed of the motor. Based on this, the present application adopts a new type of current feedback-free control, such as Figure 4 shown. Figure 3 and Figure 4 The meanings of the symbols are shown in Table 2.

[0031] Table 2 Figure 3 and Figure 4 The meaning of each symbol Figure 3 The simple removal of the current closed loop will lead to a large difference between the transfer function of the proposed control method and the real motor, so it is better to write Figure 3 The transfer function expressions of each link in are: The traditional motor simulation system control method will distort the current waveform at high speed, which can be expressed in the transfer function as: in, , .

[0032] Then the transfer function of current closed-loop control can be obtained: After removing the current closed loop, non-feedback current control is adopted, such as Figure 4 As shown, in order to keep consistent with the transfer function of the real motor, impedance adjustment control needs to be added. The transfer function of the impedance controller is for: in, is the transfer function of the permanent magnet synchronous motor, is the stator resistance, is the stator inductance, is the transfer function of the filter inductor, is the filter inductor impedance, For the filter inductor.

[0033] Transfer function of the permanent magnet synchronous motor simulation system according to the embodiment of the present invention for: in, is the transfer function of the speed loop controller, is the transfer function of the impedance controller, is the angular velocity of the preset frequency.

[0034] It can ensure that the current waveform is not distorted when the motor speed is high, and it can still remain stable when the speed changes suddenly. Possible values: .

[0035] Figure 5 It is a comparison of the Bode diagrams of the real motor, current closed-loop control and the current feedback-free control of this application, where G-stator is the Bode diagram of the real motor, G-new is the Bode diagram of the permanent magnet synchronous motor simulation system of this application, and G-CLCC is the Bode diagram of the current closed-loop control. It can be found that at high frequencies (800Hz), the amplitude of the transfer function of the permanent magnet synchronous motor simulation system of this application is close to that of the actual motor, verifying the correctness of the control strategy.

[0036] Based on the above analysis, we can know the signal flow of the entire permanent magnet synchronous motor simulation system: after the three-phase voltage is sampled, it passes through the decoupling control of the motor and is input to the impedance regulation controller and the feedback-free current control. The output current part is used for the mechanical equation and torque equation of the motor, and the output voltage part is used as the modulation voltage of the second inverter. dq The signal flow diagram below the axis is as follows Figure 6shown.

[0037] In order to meet the requirements of testing dynamic and steady-state performance in a short time scale, the working condition simulation needs to follow the following principles: First, the reference speed of the given motor is to rise to a steady state at a constant speed to cover a wide speed range, and there cannot be any sudden changes in speed, otherwise the drive system will be unstable.

[0038] Second, the load mechanical torque is designed to be a non-periodic step change, which can remain stable at high speeds while taking into account the electromagnetic torque characteristics and current characteristics.

[0039] The working condition simulation condition can be: given an initial reference speed; control the preset reference speed to rise from the initial reference speed to the target speed. Determine the initial value of the motor's load torque, and control the load torque to jump from the initial value of the load torque to the preset torque at a preset time point. For example, the given reference speed is 60r / min, and this step is to simulate the soft start process of HSPMSM. At 0.5s, the given reference speed starts to rise until it reaches 24000r / min. The initial value of the motor's load torque is 2N m, step to 1N in 3s m.

[0040] The permanent magnet synchronous motor simulation system of the embodiment of the present invention solves the problem in the prior art that current and speed oscillations may occur in the motor simulation control system when running at high speed. When the load suddenly changes at high speed, the motor simulation system can still remain stable, successfully achieving the dynamic response effect of the motor simulation system at a high frequency of 800Hz.

[0041] In order to verify the effectiveness of the proposed control method, Figure 4 and Figure 5 The flowchart in the figure is used to build a simulation in the software PLECS. At the same time, in order to compare the motor simulation system with the actual motor model, the waveforms of key parameters such as current, speed, and torque are measured using an oscilloscope. Figure 7 and Figure 8 As shown, Figure 7 (a) and Figure 8 (a) is the actual motor, Figure 7 (b) and Figure 8 (b) is a simulation system of a permanent magnet synchronous motor. The waveforms are compared and analyzed one by one below.

[0042] exist Figure 7 It can be seen that the current waveform of the actual motor and the current waveform of the motor simulation system are basically consistent. When the speed reaches 24000r / min, the current waveform of the motor simulation system is still consistent with the actual motor. At this time, according to the speed calculation formula Available, frequency , it can still remain stable under high frequency conditions, achieving a dynamic response effect at a high frequency of 800Hz. Secondly, the current waveforms of both can be divided into four parts.

[0043] The first part, 0-0.5s, at this time the motor speed is very low, in the soft start process, the current rises in a sinusoidal wave; The second part, 0.5-3s, after 0.5s, the motor speed is in a steady increase stage, at this time the given load torque is 2 ; The third part, 3-4.5s, after 3s, the given load torque is 2 Step is 1 , the current decreases, but the rate of increase of the motor speed is still consistent with the second part; Part 4: After 4.5s, the motor speed does not change and stabilizes at 24000r / min, and the load torque stabilizes at 1 , the motor is in a stable working state.

[0044] from Figure 8 It can be seen from the speed and torque waveforms that the motor is in the soft start process within the first 0.5s, and then the motor speed steadily increases until it reaches 24000r / min. The changes in the torque waveforms of the two are also basically the same. Table 3 shows the relationship between the speed, load torque, and electromagnetic torque in different intervals during the startup process.

[0045] Table 3 Relationship between speed, load torque and electromagnetic torque in different ranges In the embodiment of the present invention, the first converter adopts the conventional The vector control mode is set to voltage type. Given a reference speed that rises at a constant speed, the output voltage of the speed outer loop is used as the modulation voltage of the first converter. The collected three-phase voltage is used as the input of the impedance regulator, and then the feedback current is output through the feedbackless current control link. , Figure 4 In That is Figure 1 The three-phase current is collected in the circuit, and then input into the current outer loop as feedback. At the same time, the voltage output by the impedance regulation control link is used as the modulation voltage of the second converter. Finally, the simulation waveforms of the actual motor and the permanent magnet synchronous motor simulation system are compared and analyzed, and it is concluded that the permanent magnet synchronous motor system of the embodiment of the present invention solves the problem of current and speed oscillation in the permanent magnet synchronous motor simulation control system in the prior art when running at high speed. When the speed and load suddenly change, the permanent magnet synchronous motor simulation system can still remain stable, and the stable operation of the motor simulation system at high frequency speed is successfully achieved.

[0046] In summary, the permanent magnet synchronous motor simulation system of the present application includes: a first converter, a second converter, an impedance controller, a current feedback-free controller, a filter inductor, a current Hall sensor and a speed loop controller; the first converter and the second converter are connected in three phases through the filter inductor; the impedance controller is connected to the connecting branch of the first converter and the second converter, and is connected to the current feedback-free controller, and is used to control and process the three-phase sampling voltage collected from the connecting branch in combination with the current feedback-free controller, and the output voltage is used as the modulation voltage of the second converter; the current Hall sensor is arranged on the connecting branch for collecting three-phase current; the speed loop controller is connected to the first converter, and is used to control the output modulation voltage according to the input preset reference speed and the collected three-phase current and transmit it to the first converter. Through the impedance adjustment control, current feedback-free control and frequency compensation methods, the problem of inconsistency between the motor simulation control system and the actual motor in the prior art when running at high speed is solved, and the current and torque waveforms of the motor simulation system at high speed are not distorted, and the stability of the motor simulation system can still be guaranteed in the case of sudden load changes, which effectively improves the stability of the simulation system.

[0047] Fig. 9 FIG. 1 is a flow chart of a control method for a permanent magnet synchronous motor simulation system provided by an embodiment of the present invention, the method comprising: Step S11, inputting a preset reference speed into the speed loop controller, and controlling the first converter to operate in a voltage-based operating mode.

[0048] Optionally, an initial reference speed is given; the preset reference speed is controlled to rise from the initial reference speed to the target speed. At the same time, the initial value of the load torque of the motor is determined, and the load torque is controlled to step from the initial value of the load torque to the preset torque at a preset time point. For example, the given reference speed is 60r / min. This step is to simulate the soft start process of HSPMSM. At 0.5s, the given reference speed starts to rise until it reaches 24000r / min. The initial value of the load torque of the motor is , at 3s, it jumps to .

[0049] And control the first converter to adopt The vector control method is adopted and it works in voltage type working mode.

[0050] Step S12: using the voltage output by the impedance controller according to the collected three-phase sampled voltage as the modulation voltage of the second converter, and combining with the current non-feedback controller to control the output feedback current.

[0051] Optionally, the collected three-phase sampled voltage is input into an impedance controller, and the voltage output after proportional and integral processing by the impedance controller is used as the modulation voltage of the second converter; according to the voltage output by the impedance controller, a current feedback-free controller is applied in combination with filter inductance processing to output feedback current.

[0052] Step S13, obtaining the mechanical angular velocity of the permanent magnet synchronous motor according to the feedback current and the PMSM model.

[0053] The mechanical angular velocity is the feedback speed. , delay one sampling delay period Then it is used as the input of the speed loop controller.

[0054] Step S14, applying the speed loop controller to obtain a reference current according to the reference speed and mechanical angular velocity combined with the proportional and integral processing of the speed loop, and combining the reference current and the collected three-phase current to control the output modulation voltage of the permanent magnet synchronous motor, which is input to the first converter.

[0055] Optionally, a speed loop controller is used to calculate the difference between the reference speed and the mechanical angular velocity; the control difference is processed by the speed loop proportionally and integrally to obtain the reference current; and the collected current is delayed by a sampling period. The three-phase current is subtracted and the modulation voltage of the permanent magnet synchronous motor is output after the proportional and integral processing of the current loop.

[0056] The control method of the permanent magnet synchronous motor simulation system of the embodiment of the present invention solves the problem in the prior art that the motor simulation control system is inconsistent with the actual motor when running at high speed. It takes into account the dynamic performance of motor speed and load mutations as well as the steady-state performance when running at high speed, and realizes the application of the motor simulation system without distortion of current waveform and torque waveform when running at high speed. It can also ensure the stability of the motor simulation system in the case of load mutation, thereby effectively improving the stability of the simulation system.

[0057] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0058] The above is only a partial implementation of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A permanent magnet synchronous motor simulation system, characterized in that: The permanent magnet synchronous motor simulation system includes: a first converter, a second converter, an impedance controller, a current feedback-free controller, a filter inductor, a current Hall sensor and a speed loop controller; the first converter and the second converter are connected in three phases through the filter inductor; the impedance controller is connected to the connecting branch between the first converter and the second converter, and is connected to the current feedback-free controller, and is used to control and process the three-phase sampling voltage collected from the connecting branch in combination with the current feedback-free controller, and the output voltage is used as the modulation voltage of the second converter; the current Hall sensor is arranged on the connecting branch, and is used to collect three-phase current; the speed loop controller is connected to the first converter, and is used to control the output modulation voltage according to the input preset reference speed and the collected three-phase current and transmit it to the first converter.

2. The permanent magnet synchronous motor simulation system according to claim 1, characterized in that: The first converter adopts the reference current of the permanent magnet synchronous motor d The axis component is zero vector control mode and is set to voltage type working mode.

3. The permanent magnet synchronous motor simulation system according to claim 1, characterized in that: The transfer function of the impedance controller is for: in, represents the Laplace transform domain, is the transfer function of the permanent magnet synchronous motor, is the stator resistance, is the stator inductance, is the transfer function of the filter inductor, is the filter inductor impedance, For the filter inductor.

4. The permanent magnet synchronous motor simulation system according to claim 1, characterized in that: The transfer function of the permanent magnet synchronous motor simulation system for: in, is the transfer function of the speed loop controller, is the transfer function of the impedance controller, is the angular velocity of the preset frequency.

5. The permanent magnet synchronous motor simulation system according to claim 1, characterized in that: The permanent magnet synchronous motor simulation system also includes: a coordinate transformer, which is connected between the current Hall sensor and the speed loop controller and is used to perform coordinate transformation on the three-phase current collected by the current Hall sensor and output the result to the speed loop controller.

6. A control method for a permanent magnet synchronous motor simulation system according to any one of claims 1 to 5, characterized in that: The control method comprises: Inputting a preset reference speed into the speed loop controller, and controlling the first converter to operate in a voltage-based operating mode; The impedance controller is used to output a voltage according to the collected three-phase sampling voltage as a modulation voltage of the second converter, and the output feedback current is controlled in combination with the current feedback-free controller; Obtaining the mechanical angular velocity of the permanent magnet synchronous motor according to the feedback current in combination with a PMSM model; The speed loop controller is applied to obtain a reference current according to the reference speed and the mechanical angular velocity combined with the proportional and integral processing of the speed loop, and the modulation voltage of the output permanent magnet synchronous motor is controlled and input into the first converter in combination with the reference current and the collected three-phase current.

7. The control method according to claim 6, characterized in that: The inputting a preset reference speed into the speed loop controller comprises: Given an initial reference speed; The preset reference speed is controlled to increase from the initial reference speed to the target speed.

8. The control method according to claim 7, characterized in that: The step of inputting a preset reference speed to the speed loop controller further includes: An initial value of the load torque of the motor is determined, and the load torque is controlled to step from the initial value of the load torque to a preset torque at a preset time point.

9. The control method according to claim 6, characterized in that: The voltage output by the impedance controller according to the collected three-phase sampled voltage is used as the modulation voltage of the second converter, and the output feedback current is controlled in combination with the current feedback-free controller, including: Inputting the collected three-phase sampled voltage into an impedance controller, and outputting a voltage after proportional and integral processing by the impedance controller as a modulation voltage of the second converter; According to the voltage output by the impedance controller, a current non-feedback controller is applied in combination with a filter inductor to output a feedback current.

10. The control method according to claim 6, characterized in that: The application of the speed loop controller obtains a reference current according to the reference speed and the mechanical angular velocity in combination with the proportional and integral processing of the speed loop, and controls the modulation voltage of the output permanent magnet synchronous motor in combination with the reference current and the collected three-phase current, including: Applying the speed loop controller to calculate the difference between the reference speed and the mechanical angular velocity; Controlling the difference to obtain a reference current after the difference is processed by the proportional and integral of the speed loop; The difference is made with the collected three-phase current after a sampling delay period, and the modulation voltage of the permanent magnet synchronous motor is output after the proportional and integral processing of the current loop.

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