Method for establishing analysis model for surface permanent magnet synchronous motor, and motor control method

Abstract

Disclosed in the present application are a method for establishing an analysis model for a surface permanent magnet synchronous motor, and a motor control method. The method for establishing an analysis model for a surface permanent magnet synchronous motor comprises: first, establishing vector magnetic circuit models for a surface permanent magnet synchronous motor, regarding the arc tangent value of the ratio of equivalent magnetic reactance to magnetic reluctance as an iron loss angle, and using the iron loss angle to reflect the impact of an eddy current effect and a magnetic hysteresis effect, which cause iron losses, on motor performance and motor control; on the basis of vector magnetic circuits, providing (I) coordinate transformation and an (I) coordinate system; and then establishing an analysis model for the surface permanent magnet synchronous motor, which analysis model comprises a flux linkage equation and a voltage equation that are based on the vector magnetic circuits and the (I) coordinate system, and on the basis of the provided analysis model, establishing a position-sensor-free control method for the surface permanent magnet synchronous motor. The present application fully takes into consideration the impact of an eddy current effect and a magnetic hysteresis effect, which cause iron losses, on motor performance and motor control, is simple and convenient, and has clear physical significance, thereby improving the accuracy of rotor position identification in the position-sensor-free control for a surface permanent magnet synchronous motor.

Description

Analysis Model Establishment Method and Motor Control Method for Surface-Mounted Permanent Magnet Synchronous Motor Technical Field

[0001] This invention belongs to the field of motor control technology, specifically relating to a coordinate transformation based on vector magnetic circuits and an analysis and control method for surface-mounted permanent magnet synchronous motors. Background Technology

[0002] Surface-mounted permanent magnet synchronous motors (SPMSMs) are widely used in industry, electric vehicles, and home appliances due to their advantages such as simple structure, high power density, wide speed range, and high efficiency. The performance of SPMSMs is not only affected by the motor's structure, but the control algorithm also plays a crucial role. Vector control is one of the most common control methods for SPMSMs. Vector control requires mechanical sensors to provide position information, but sensors inevitably face problems such as hardware failure, reduced reliability, space occupation, and increased cost. To solve and overcome these problems, sensorless control strategies have emerged.

[0003] In sensorless control, the motor model plays a crucial role because rotor position and speed information are estimated based on the voltage-current relationship. Therefore, establishing a more accurate analytical model for permanent magnet synchronous motors is essential. Iron losses (caused by eddy currents and hysteresis) are inevitable during motor operation; however, most studies on sensorless control of surface-mounted permanent magnet synchronous motors are conducted without considering the impact of iron losses. Using traditional analytical models that do not consider iron losses will affect the performance of sensorless control systems for surface-mounted permanent magnet synchronous motors, especially during medium- and high-speed operation.

[0004] Professor Cheng Ming's team at Southeast University discovered the phenomena of magnetic induction and magnetocapacitance in magnetic circuits, established a vector magnetic circuit theory containing three elements—resistance, magnetic induction, and magnetocapacitance—and a magnetoelectric power law, providing a new method for considering iron losses in motors, different from using equivalent resistance. The active power loss caused by the magnetic induction element corresponds to eddy current losses in the magnetic circuit, while the active power loss caused by the magnetocapacitance element corresponds to hysteresis losses. Introducing magnetic induction and magnetocapacitance into the permanent magnet synchronous motor model allows consideration of the influence of eddy current and hysteresis effects on the permanent magnet flux and the stator flux excited by the armature current. Based on the vector magnetic circuit theory, a novel analytical model and control method for permanent magnet synchronous motors can be established. Because this model considers both the magnetic circuit and the electrical circuit, the introduction of iron losses is more rationally justified, but its form is also more complex. In this analytical model, the flux linkage equation introduces the coupling between the d-axis current and the q-axis flux linkage, as well as the coupling between the q-axis current and the d-axis flux linkage. The voltage equation adds differential coupling terms between the d-axis current and the q-axis current and a rotating electromotive force component. The addition of these coupling terms makes the motor model closer to the actual operation of the motor, but increases the design difficulty of the motor's sensorless control system. Summary of the Invention

[0005] The purpose of this invention is to propose a coordinate transformation and surface-mounted permanent magnet synchronous motor analysis model based on vector magnetic circuits, and a motor control method based on this motor analysis model.

[0006] The coordinate transformation based on vector magnetic circuit and the analysis model of the surface-mounted permanent magnet synchronous motor (SPMSM) of this invention are as follows: magnetic induction is introduced into the d-axis and q-axis magnetic circuit models of the SPMSM. With magnetocapacitance C, construct d-axis and q-axis vector magnetic circuit models, and convert the equivalent magnetic reactance... With magnetic resistance The arctangent of the ratio is regarded as the iron loss angle δ of the surface-mounted permanent magnet synchronous motor SPMSM; the iron loss angle is used to characterize the influence of eddy currents and hysteresis effects that cause iron loss on the stator flux linkage and permanent magnet flux linkage;

[0007] propose coordinate system and Coordinate transformation matrix T δ ′, the The coordinate system lags the dq coordinate system by an iron loss angle δ, based on the vector magnetic circuit and A coordinate system is used to establish an analysis model for a surface-mounted permanent magnet synchronous motor, including models based on vector magnetic circuits and... The flux linkage equation and voltage equation in the coordinate system;

[0008] Furthermore, the iron loss angle δ of the surface-mounted permanent magnet synchronous motor SPMSM is expressed as:

[0009] make

[0010] k is the equivalent magnetic flux density;

[0011] Since magnetic reluctance is expressed as

[0012] Therefore, the iron loss angle of the surface-mounted permanent magnet synchronous motor (SPMSM) is expressed as: δ=arctan(ωL) s k) (3)

[0013] in, Let C be the magnetic induction in the dq coordinate system, and C be the magnetic capacitance in the dq coordinate system. The equivalent magnetic field in the dq coordinate system. Let L be the reluctance in the dq coordinate system. s Let δ be the inductance in the dq coordinate system, k be the equivalent magnetic flux density, δ be the iron loss angle, ω be the rotor electric angular velocity, and N be the number of turns in the armature winding.

[0014] Furthermore, Coordinate transformation matrix T δ ′, represented as:

[0015] Furthermore, the flux linkage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system is obtained:

[0016] Multiplying both sides of equation (6) by cosδ, the flux linkage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system can also be written as:

[0017] d-axis and q-axis flux linkage Coordinate transformation matrix T δ After transformation, we get shaft and Axial magnetic flux;

[0018] From equation (7), we obtain the vector magnetic circuit and The flux linkage equations of a surface-mounted permanent magnet synchronous motor in a coordinate system are as follows:

[0019] Furthermore, The voltage equations for a surface-mounted permanent magnet synchronous motor in the coordinate system are as follows:

[0020] According to the relationship And equation (8), replacing the d-axis and q-axis currents. shaft and shaft current, then shaft and The magnetic flux linkage is represented by the d-axis and q-axis currents, obtained from equation (9):

[0021] Because of R s sinδ << ωL s cosδ, ignoring R in equation (10) s sinδ, according to equation (10), is derived based on the vector magnetic circuit and The voltage equation for a surface-mounted permanent magnet synchronous motor in a coordinate system is written as follows:

[0022] in, and for Magnetic flux linkage in coordinate system and for Voltage in coordinate system and for Current in coordinate system, L s Let R be the inductance in the dq coordinate system. s Let ψ be the resistance in the dq coordinate system. f δ is the permanent magnet flux linkage, ω is the iron loss angle, ω is the rotor electric angular velocity, and p is the differential operator.

[0023] Furthermore, by expressing the voltage term on the left side of equation (10) in the dq coordinate system, we obtain the voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system:

[0024] Performing an inverse Clark transformation on equation (12), we obtain the voltage equation for a surface-mounted permanent magnet synchronous motor based on a vector magnetic circuit in the α-β coordinate system:

[0025] Among them, i α and i β Let u be the current in the α-β coordinate system. d and u q Let θ be the voltage in the dq coordinate system, and θ be the electrical angle of the rotor position.

[0026] Based on the surface-mounted permanent magnet synchronous motor analysis model of this invention, this invention also proposes a vector magnetic circuit and A sensorless control method for a surface-mounted permanent magnet synchronous motor in a coordinate system includes the following steps:

[0027] Sample values ​​are obtained by sampling the three-phase current of the motor. Will The current sampling value in the α-β coordinate system is obtained after the Clark transformation module. and Then and The current sampling value in the dq coordinate system is obtained through the Park transformation module. and Rotor speed observation value The error between the current and the setpoint n is used by the PI controller to obtain the d-axis and q-axis current setpoints i. d and i q ,Will and with i d and i q The errors are input into two PI controllers respectively, and the results are obtained. Voltage setpoint in coordinate system and Using the Park inverse transform module, based on angle Perform the inverse Park transform, and Voltage setpoint in coordinate system and The voltage setpoint u in the α-β coordinate system is obtained by transformation. α and u β , use u α and u β The synthesized voltage space vector is modulated by the input voltage space vector modulation module, and the output state code values ​​of the three half-bridges at that moment are used to control the switching of the MOSFETs in the three-phase inverter to control the motor; wherein... This represents the observed rotor position angle.

[0028] The rotor speed observation value and rotor position angle observations Output from the rotor position and speed observation module;

[0029] The voltage of the input rotor position and speed observation module is

[0030] The current input to the rotor position and speed observation module is the current sample value in the α-β coordinate system. and

[0031] Compared with existing models, the above model has the following technical advantages:

[0032] (1) The motor analysis model proposed in this invention, which utilizes the equivalent magnetic induction parameters and the influence of iron loss, can take into account the influence of eddy currents and hysteresis effects that cause iron loss on motor performance and control, and is closer to the actual operating conditions of the motor, thus having higher analysis and control accuracy.

[0033] (2) Based on the vector control of the present invention, the voltage is corrected based on the iron loss angle in the Park inverse transformation, which enhances the decoupling degree of the d-axis and q-axis current loops, making the step response of the surface-mount permanent magnet synchronous motor faster and the current waveform more stable, thus improving the performance of vector control.

[0034] (3) Unlike the traditional method of using resistance to represent iron loss, the motor analysis model proposed in this invention, which uses equivalent magnetic induction parameters to account for the influence of iron loss, is derived by simultaneously considering the magnetic circuit and electrical circuit relationships, making the introduction of iron loss more theoretically grounded. Moreover, it is simpler than the model that uses resistance to consider iron loss, and in form, it is similar to the traditional surface-mounted permanent magnet synchronous motor analysis model that does not consider the influence of iron loss. The traditional sensorless control method for surface-mounted permanent magnet synchronous motors can be used in the invented analysis model with simple improvements, enabling the design of a sensorless control system with higher control accuracy. Attached Figure Description

[0035] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 is a flowchart of a coordinate transformation and surface-mounted permanent magnet synchronous motor analysis and control method based on vector magnetic circuit according to the present invention.

[0037] Figure 2 illustrates the establishment of this invention. Schematic diagram of coordinate system;

[0038] Figure 3 shows the present invention based on vector magnetic circuit and Block diagram of a sensorless control method for a coordinate system;

[0039] Figure 4 is a simulation diagram of the control method of the present invention;

[0040] Figure 5 is a simulation diagram of the sensorless control effect of the present invention at a rotation speed of 1200 r / min;

[0041] Figure 6 is a simulation diagram of the sensorless control effect of the present invention at a rotation speed of 3000 r / min. Detailed Implementation

[0042] Referring to Figures 1-3 and the content of this invention, a specific embodiment of a coordinate transformation and surface-mounted permanent magnet synchronous motor analysis and control method based on vector magnetic circuits is presented. Figures 4-6 show the simulation results of this specific embodiment, verifying the effectiveness of this invention. The described embodiments are only a part of the embodiments of this invention, not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] This invention proposes a coordinate transformation based on vector magnetic circuits and an analysis and control method for surface-mounted permanent magnet synchronous motors, comprising the following steps:

[0044] Step 1: Establish the d-axis and q-axis vector magnetic circuit models of the surface-mounted permanent magnet synchronous motor, and combine the equivalent magnetic reactance and magnetic reluctance. The arctangent of the ratio is regarded as the iron loss angle, and the iron loss angle is used to induce the influence of eddy currents and hysteresis effects of iron loss on the stator flux linkage and permanent magnet flux linkage.

[0045] Introducing magnetic induction into the d-axis and q-axis magnetic circuit models of a surface-mounted permanent magnet synchronous motor. Using two vector magnetic circuit parameters, C and magnetocapacitance C, construct d-axis and q-axis vector magnetic circuit models, and use magnetic induction... The magnetic capacitance C characterizes the magnitude of the eddy currents and hysteresis effects that induce iron losses; magnetic induction Both the magnetic flux and the magnetic capacitance C cause the magnetic flux to lag behind the magnetomotive force or current, therefore the equivalent magnetic induction parameter can be used. Equivalent magnetic induction The combined effect of magnetic flux and magnetocapacitance C, taking into account the influence of iron loss; in the d-axis and q-axis vector magnetic circuit model, the angle by which the magnetic flux lags behind the magnetomotive force or current is the iron loss angle δ, which can be expressed as:

[0046] make:

[0047] k is called the equivalent magnetic flux density, which can be measured experimentally. In this invention, the change in the equivalent magnetic flux density is not considered, and it is assumed to be a fixed parameter. Since the magnetic reluctance can be expressed as... The iron loss angle of a surface-mounted permanent magnet synchronous motor can be expressed as: δ=arctan(ωL) s k) (3)

[0048] In equation (1-3), Let C be the magnetic induction in the dq coordinate system, and C be the magnetic capacitance in the dq coordinate system. The equivalent magnetic field in the dq coordinate system. Let L be the reluctance in the dq coordinate system. s Let be the inductance in the dq coordinate system, k be the equivalent magnetic flux density, δ be the iron loss angle, ω be the rotor electric angular velocity, and N be the number of turns in the armature winding.

[0049] Step 2: Propose a Coordinate transformation and The coordinate system is shown in Figure 2. The coordinate system lags behind the dq coordinate system by one iron loss angle, based on the vector magnetic circuit and A coordinate system is used to establish an analysis model for a surface-mounted permanent magnet synchronous motor, including models based on vector magnetic circuits and... The flux linkage equation and voltage equation in the coordinate system;

[0050] Equivalent magnetic induction parameters are introduced into the d-axis and q-axis magnetic circuit equations of the surface-mounted permanent magnet synchronous motor. Then, by performing the Parker transformation, we obtain the magnetic circuit equations along the d-axis and q-axis in the dq coordinate system:

[0051] In equation (4), and Let Φ be the magnetomotive force in the dq coordinate system. d and Φ q Let i be the magnetic flux in the dq coordinate system. d and i q Let be the current in the dq coordinate system. For the reluctance in the dq coordinate system, L is the equivalent magnetic field in the dq coordinate system. s Let ψ be the inductance in the dq coordinate system. f ω is the permanent magnet flux linkage, N is the rotor electric angular velocity, and p is the differential operator.

[0052] When the motor is running stably, it is assumed that the magnetic circuits of the d-axis and q-axis are in a stable state. Further, we can obtain:

[0053] Combining equations (3) and (5), we can obtain the flux linkage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system:

[0054] Furthermore, multiplying both sides of equation (6) by cosδ, we get:

[0055] In equation (7), for The coordinate transformation matrix is ​​a matrix that rotates the dq coordinate system in the hysteresis direction by an iron loss angle δ, thereby obtaining a new coordinate system. coordinate system The coordinate system lags behind the dq coordinate system by an angle δ;

[0056] In equation (5-7), ψ d and ψ q Let i be the flux linkage in the dq coordinate system. d and i q Let L be the current in the dq coordinate system. s Let ψ be the inductance in the dq coordinate system. f ω is the magnetic flux linkage of the permanent magnet, and ω is the electric angular velocity of the rotor;

[0057] d-axis and q-axis voltages (magnetic flux) via T δ After transformation, we get shaft and Voltage (magnetic flux), which can be further obtained based on vector magnetic circuits and The flux linkage equations of a surface-mounted permanent magnet synchronous motor in a coordinate system are as follows:

[0058] Voltage equations for surface-mounted permanent magnet synchronous motors in coordinate system:

[0059] Furthermore, based on the relationship And equation (8), replacing the d-axis and q-axis currents. shaft and shaft current, then shaft and The magnetic flux linkage is represented by the d-axis and q-axis currents, which can be obtained from equation (9):

[0060] Because of R s sinδ << ωL s cosδ, ignoring R in equation (10) s sinδ, according to equation (10), is derived based on the vector magnetic circuit and Voltage equations for a surface-mounted permanent magnet synchronous motor in a coordinate system:

[0061] Expressing the voltage term on the left side of equation (10) in the dq coordinate system, we can obtain the voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system:

[0062] Performing an inverse Clark transformation on equation (12), we can obtain the voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the α-β coordinate system:

[0063] In equation (8-13), and for Magnetic flux linkage in coordinate system and for Voltage in coordinate system, u d and u q Let u be the voltage in the dq coordinate system. α and u β Let i be the voltage in the α-β coordinate system. d and i q Let i be the current in the dq coordinate system. α and i β Let L be the current in the α-β coordinate system. s Let R be the inductance in the dq coordinate system. s Let ψ be the resistance in the dq coordinate system. f denoted as permanent magnet flux linkage, δ as iron loss angle, ω as rotor electric angular velocity, θ as rotor position electric angle, and p as differential operator.

[0064] Step 3: Establish a vector magnetic circuit and A sensorless control method for surface-mounted permanent magnet synchronous motors in a coordinate system.

[0065] Based on the above vector magnetic circuit and An analytical model of a surface-mounted permanent magnet synchronous motor is established using a coordinate system. A method based on vector magnetic circuits and... The sensorless control method for a coordinate system is as follows:

[0066] The collaborative working process of each module is shown in Figure 3, where the three-phase current of the motor is sampled to obtain sampled values. Will The current sampling values ​​in the α-β coordinate system are obtained after the Clark transformation module (abc / αβ). and Then and The current sampling value in the dq coordinate system is obtained after the Park transformation module (αβ / dq). and The error between the rotor speed and the speed setpoint is processed by a PI controller to obtain the d-axis and q-axis current setpoints i. d and i q ,Will and with i d and i q The error is input to two PI controllers (PI), and the result is... Voltage setpoint u in coordinate system R and u L Based on angle The voltage setpoint u in the α-β coordinate system is obtained after the Park inverse transform module (dq / αβ). α and u β , use u α and u β The synthesized voltage space vector is modulated by the input voltage space vector modulation module (SVPWM) and outputs the state code values ​​of the three half-bridges at that moment. The MOSFETs of the three-phase inverter are controlled to switch and control the motor. The rotor speed and rotor position angle used are provided by the rotor position and speed observation module (SMO).

[0067] The Park inverse transform module in this invention is to... The voltage is transformed from the coordinate system to the voltage in the α-β coordinate system. The angle input to the Park inverse transform module is the observed rotor position angle. Subtract the iron loss angle δ, that is

[0068] The rotor position and speed observation module in this invention is designed according to equation (13), and the voltage information input to the rotor position and speed observation module (SMO) is:

[0069] A sensorless vector control simulation was performed on a surface-mounted permanent magnet synchronous motor (SPMSM). First, the motor speed was adjusted to 1200 r / min with a load of 7.7 N·m. Then, the speed was increased to 3000 r / min, and the load was reduced by 2 N·m. The step response speed and current waveform stability were observed, and the effectiveness of the control method of this invention was compared with that of the traditional vector control method. The SPMSM was controlled at 1200 r / min and 3000 r / min to identify rotor position and speed information. The sensorless control based on the model of this invention was compared with the traditional sensorless control. The errors between the observed rotor position and speed information and the actual values ​​were compared to verify the feasibility and effectiveness of the proposed motor analysis model and control method. The parameters of the surface-mounted permanent magnet synchronous motor in the simulation are shown in the table below.

[0070] As shown in Figure 4, using i d =0 control, control i d The vector control i proposed in this invention remains unchanged during the speed regulation and load reduction process. d The fluctuations are smaller, which improves the speed and stability of vector control in responding to step changes.

[0071] As shown in Figures 5 and 6, the sensorless control based on the model of this invention improves the rotor position observation accuracy compared with the traditional sensorless control. The error is reduced by about 0.2 electrical angles at 1200 r / min and by about 0.7 electrical angles at 3000 r / min. Comparing Figures 5 and 6, at higher speeds, iron losses are also greater, causing traditional sensorless control to produce larger identification errors. The sensorless control based on the model of this invention is more effective in improving the error.

[0072] The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the invention should fall within the scope of protection defined by the claims of the present invention.

Claims

1. An analytical model for a surface-mounted permanent magnet synchronous motor, characterized in that, Magnetic induction is introduced into the d-axis and q-axis magnetic circuit models of the surface-mounted permanent magnet synchronous motor (SPMSM). With magnetocapacitance C, construct d-axis and q-axis vector magnetic circuit models, and convert the equivalent magnetic reactance... With magnetic resistance The arctangent of the ratio is considered as the iron loss angle δ of the surface-mounted permanent magnet synchronous motor SPMSM; propose coordinate system and Coordinate transformation matrix T δ ′;The The coordinate system lags the dq coordinate system by an iron loss angle δ. Coordinate transformation matrix T δ Transform the dq coordinate system to Coordinate system; Based on vector magnetic circuit and A coordinate system is used to establish an analysis model for a surface-mounted permanent magnet synchronous motor, including models based on vector magnetic circuits and... The magnetic flux linkage equation and voltage equation in the coordinate system.

2. The surface-mounted permanent magnet synchronous motor analysis model according to claim 1, characterized in that, The iron loss angle δ of the surface-mounted permanent magnet synchronous motor SPMSM is expressed as: make k is the equivalent magnetic flux density; since the reluctance is expressed as Therefore, the iron loss angle of the surface-mounted permanent magnet synchronous motor SPMSM is expressed as: δ=arctan(ωL s k) (3) in, Let C be the magnetic induction in the dq coordinate system, and C be the magnetic capacitance in the dq coordinate system. The equivalent magnetic field in the dq coordinate system. Let L be the reluctance in the dq coordinate system. s Let be the inductance in the dq coordinate system, k be the equivalent magnetic flux density, δ be the iron loss angle, ω be the rotor electric angular velocity, and N be the number of turns in the armature winding.

3. The surface-mounted permanent magnet synchronous motor analysis model according to claim 2, characterized in that, Coordinate transformation matrix T δ ′, represented as:

4. The surface-mounted permanent magnet synchronous motor analysis model according to claim 3, characterized in that, The flux linkage equations of the surface-mounted permanent magnet synchronous motor based on vector magnetic circuits in the dq coordinate system are obtained as follows: Multiplying both sides of equation (6) by cosδ, the flux linkage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system can also be written as: d-axis and q-axis flux linkage Coordinate transformation matrix T δ After transformation, we get shaft and Axial magnetic flux; From equation (7), we obtain the vector magnetic circuit and The flux linkage equations of a surface-mounted permanent magnet synchronous motor in a coordinate system are as follows:

5. The surface-mounted permanent magnet synchronous motor analysis model according to claim 4, characterized in that, The voltage equations for a surface-mounted permanent magnet synchronous motor in the coordinate system are as follows: According to the relationship And equation (8), replacing the d-axis and q-axis currents. shaft and shaft current, then shaft and The magnetic flux linkage is represented by the d-axis and q-axis currents, obtained from equation (9): Because of R s sinδ << ωL s cosδ, ignoring R in equation (10) s sinδ, according to equation (10), is derived based on the vector magnetic circuit and The voltage equations for a surface-mounted permanent magnet synchronous motor in a coordinate system are written as follows: in, and for Magnetic flux linkage in coordinate system and for Voltage in coordinate system and for Current in coordinate system, L s Let R be the inductance in the dq coordinate system. s Let ψ be the resistance in the dq coordinate system. f δ is the permanent magnet flux linkage, ω is the iron loss angle, ω is the rotor electric angular velocity, and p is the differential operator.

6. The surface-mounted permanent magnet synchronous motor analysis model according to claim 5, characterized in that, Expressing the voltage term on the left side of equation (10) in the dq coordinate system, we obtain the voltage equation for the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the dq coordinate system: Performing an inverse Clark transformation on equation (12), we obtain the voltage equation for a surface-mounted permanent magnet synchronous motor based on a vector magnetic circuit in the α-β coordinate system: Among them, i α and i β Let u be the current in the α-β coordinate system. d and u q Let θ be the voltage in the dq coordinate system, and θ be the electrical angle of the rotor position.

7. A motor control method based on the surface-mounted permanent magnet synchronous motor analysis model as described in claim 6, characterized in that, Includes the following steps: Sample values ​​are obtained by sampling the three-phase current of the motor. Will The current sampling value in the α-β coordinate system is obtained after the Clark transformation module. and Then and The current sampling value in the dq coordinate system is obtained through the Park transformation module. and Rotor speed observation value The error between the current and the setpoint n is used by the PI controller to obtain the d-axis and q-axis current setpoints i. d and i q ,Will and with i d and i q The errors are input into two PI controllers respectively, and the results are obtained. Voltage setpoint in coordinate system and Using the Park inverse transform module, based on angle Perform the inverse Park transform, and Voltage setpoint in coordinate system and The voltage setpoint u in the α-β coordinate system is obtained by transformation. α and u β , use u α and u β A synthesized voltage space vector is input to a voltage space vector modulation module for modulation, and the output state code values ​​of the three half-bridges are used to control the switching of the MOSFETs in the three-phase inverter to control the motor; wherein... This represents the observed rotor position angle.

8. The motor control method according to claim 7, characterized in that, The steps include: the observed rotor speed. and rotor position angle observations Output from the rotor position and speed observation module; The voltage of the input rotor position and speed observation module is The current input to the rotor position and speed observation module is the current sample value in the α-β coordinate system. and

Images