Coordinate transformation and surface-mounted permanent magnet synchronous motor analysis and control method based on vector magnetic circuit

Abstract

The invention discloses a coordinate transformation and surface-mounted permanent magnet synchronous motor analysis and control method based on a vector magnetic circuit, and the method comprises the steps: firstly, building a vector magnetic circuit model of a surface-mounted permanent magnet synchronous motor, taking an arc tangent value of a ratio of equivalent magnetic inductive reactance to magnetic resistance as an iron loss angle, the method comprises the following steps: considering the influence of eddy current and hysteresis effect which cause iron loss on motor performance and control thereof by using an iron loss angle, and proposing # imgabs0 # coordinate transformation and a # imgabs1 # coordinate system based on a vector magnetic circuit; and then, establishing a surface-mounted permanent magnet synchronous motor analysis model based on a vector magnetic circuit and a # imgabs2 coordinate system, including a flux linkage equation and a voltage equation based on the vector magnetic circuit and a # imgabs3 coordinate system, and establishing a sensorless control method based on the analysis model. The method provided by the invention can fully consider the influence of eddy current and hysteresis effect causing iron loss on the motor performance and control thereof, is simple and convenient, has clear physical significance, and improves the rotor position identification precision without position sensor control.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor control, and in particular relates to a coordinate transformation based on a vector magnetic circuit and a surface-mounted permanent magnet synchronous motor analysis and control method. Background Art

[0002] Surface permanent magnet synchronous motor (SPMSM) has the advantages of simple structure, high power density, wide speed regulation range and high working efficiency, and is widely used in industries, electric vehicles, home appliances and other fields. The performance of surface mount permanent magnet synchronous motor is not only affected by the structure of the motor body, but the control algorithm also plays a key role. Among them, vector control is one of the most common control methods for surface mount permanent magnet synchronous motor. Vector control requires mechanical sensors to provide position information, but sensors inevitably face problems such as hardware failure, reduced reliability, occupied space and increased cost. In order to solve and overcome these problems, position sensorless control strategy came into being.

[0003] In sensorless control, the motor model plays an important role because the rotor position and speed information are estimated based on the relationship between voltage and current. Therefore, it is crucial to establish a more accurate analysis model of the permanent magnet synchronous motor. Iron loss (caused by eddy current and hysteresis effects) is inevitable when the motor is running. However, most of the research on sensorless control of surface-mounted permanent magnet synchronous motors is conducted without considering the influence of iron loss. Using traditional analysis models that do not consider the influence of iron loss will affect the performance of the sensorless control system of the surface-mounted permanent magnet synchronous motor, especially when the motor is running at medium and high speeds.

[0004] Professor Cheng Ming's team from Southeast University discovered the magnetic induction and magnetic capacitance phenomena in the magnetic circuit, established the vector magnetic circuit theory containing the three elements of magnetic resistance, magnetic induction and magnetic capacitance, and the magneto-electric power law, providing a new method for considering the iron loss of the motor, which is different from the equivalent resistance. The active loss caused by the magnetic induction element corresponds to the eddy current loss in the magnetic circuit, and the active loss caused by the magnetic capacitance element corresponds to the hysteresis loss in the magnetic circuit. By introducing magnetic induction and magnetic capacitance into the permanent magnet synchronous motor model, the influence of the eddy current and hysteresis effect that cause iron loss on the permanent magnet magnetic flux and the stator magnetic flux excited by the armature current can be considered. Based on the vector magnetic circuit theory, a new permanent magnet synchronous motor analysis model and control method can be established. Since the model considers both the magnetic circuit and the circuit, the introduction of iron loss is more reasonable, but its form is also more complicated. In this analysis model, the coupling of the d-axis current and the q-axis magnetic flux and the coupling of the q-axis current and the d-axis magnetic flux are introduced into the magnetic flux equation, and the differential coupling term and the rotating electromotive force component of the d-axis current and the q-axis current are added to the voltage equation. The addition of these coupling terms makes the motor model closer to the actual operating conditions of the motor, but increases the difficulty of designing the motor's position sensorless control system. Summary of the invention

[0005] The purpose of the present invention is to propose a coordinate transformation based on a vector magnetic circuit and a surface mounted permanent magnet synchronous motor analysis model, and also propose a motor control method based on the motor analysis model;

[0006] The coordinate transformation based on the vector magnetic circuit and the surface mounted permanent magnet synchronous motor analysis model of the present invention are as follows: Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance C, construct Axis and Axis vector magnetic circuit model, the equivalent magnetic reactance With magnetic resistance The inverse tangent of the ratio is regarded as the iron loss angle of the surface mounted permanent magnet synchronous motor SPMSM ; The iron loss angle is used to characterize the influence of eddy current and hysteresis effect on stator flux and permanent magnet flux that cause iron loss;

[0007] propose Coordinate system and Coordinate transformation matrix , Coordinate system lag Coordinate system iron loss angle , based on vector magnetic circuit and Coordinate system to establish the surface mounted permanent magnet synchronous motor analysis model, including vector magnetic circuit and Coordinate system flux equation and voltage equation;

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

[0009] (1)

[0010] make

[0011] (2)

[0012] is the equivalent magnetic induction coefficient;

[0013] Since the magnetic resistance is expressed as ;

[0014] Then, the iron loss angle of the surface mounted permanent magnet synchronous motor SPMSM is expressed as:

[0015] (3)

[0016] in, for The magnetic induction in the coordinate system, C is Magnetic capacitance in the coordinate system, L eq for The equivalent magnetic induction in the coordinate system is, for The magnetic resistance in the coordinate system, for The inductance in the coordinate system, is the equivalent magnetic induction coefficient, is the iron loss angle, is the rotor electrical angular velocity, is the number of turns of the armature winding;

[0017] Furthermore, Coordinate transformation matrix , expressed as:

[0018] T d ′ = [ c o s d − s i n d s i n d c o s d ] .

[0019] Further, obtain The flux equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0020] [ 1 − t a n d t a n d 1 ] [ ψ d ψ q ] = [ L s 0 0 L s ] [ i d i q ] + [ ψ f 0 ] (6)

[0021] Multiply both sides of equation (6) by , The flux equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is also written as:

[0022] T d ′ [ ψ d ψ q ] = [ L s c o s d 0 0 L s c o s d ] [ i d i q ] + [ ψ f c o s d 0 ] (7)

[0023] Axis and Axis flux Coordinate transformation matrix After transformation, we get Axis and Axis flux linkage;

[0024] [ ψ R ψ L ] = T d ′ [ ψ d ψ q ]

[0025] Based on the vector magnetic circuit and The flux equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is:

[0026] [ ψ R ψ L ] = [ L s c o s d 0 0 L s c o s d ] [ i d i q ] + [ ψ f c o s d 0 ] (8)

[0027] Furthermore, The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is as follows:

[0028] [ u R u L ] = [ R s 0 0 R s ] [ i R i L ] + [ p ψ R p ψ L ] + [ − oh ψ L oh ψ R ] (9)

[0029] According to the relationship [ i R i L ] = T d ′ [ i d i q ] And formula (8), use Axis and Shaft current replacement Axis and The shaft current Axis and Shaft magnetic link Axis and The shaft current is expressed as follows:

[0030] [ u R u L ] = [ R s c o s d + p L s c o s d − ( R s s i n d + oh L s c o s d ) R s s i n d + oh L s c o s d R s c o s d + p L s c o s d ] [ i d i q ] + [ 0 oh ψ f c o s d ] (10)

[0031] because , ignoring the According to formula (10), the vector magnetic circuit and The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is written as:

[0032] 1 cos d [ u R u L ] = [ R s + p L s − oh L s oh L s R s + p L s ] [ i d i q ] + [ 0 oh ψ f ] (11)

[0033] in, and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, for The inductance in the coordinate system, for The resistance in the coordinate system, is the permanent magnet flux, is the iron loss angle, is the rotor electrical angular velocity, is the differential operator.

[0034] Furthermore, the voltage term on the left side of equation (10) is Expressed in the coordinate system, we get The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0035] [ 1 − t a n d t a n d 1 ] [ u d u q ] = [ R s + p L s − oh L s oh L s R s + p L s ] [ i d i q ] + [ 0 oh ψ f ] (12)

[0036] Perform Clark inverse transformation on equation (12) and we get The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0037] [ 1 − t a n d t a n d 1 ] [ u α u β ] = [ R s + p L s 0 0 R s + p L s ] [ i α i β ] + [ − oh ψ f s i n i oh ψ f c o s i ] (13)

[0038] in, and for The current in the coordinate system, and for The voltage in the coordinate system, is the rotor position in electrical degrees.

[0039] Based on the surface mounted permanent magnet synchronous motor analysis model of the present invention, the present invention also proposes a method based on vector magnetic circuit and A position sensorless control method for a surface mounted permanent magnet synchronous motor in a coordinate system includes the following steps:

[0040] Sample the three-phase current of the motor to obtain the sampled value , , ,Will , , After the Clark transformation module, we get Current sampling value in the coordinate system and , and then and After the Park transformation module, we get Current sampling value in the coordinate system and , rotor speed observation value With the set value The error is obtained by PI controller Axis and Shaft current setting value and ,Will and and and The error is input into two PI controllers respectively, and we get Voltage setting value in coordinate system and , through the Park inverse transform module, based on the angle Perform Park's inverse transform and Voltage setting value in coordinate system and Transformation Voltage setting value in coordinate system and ,use and The synthesized voltage space vector is modulated by the input voltage space vector modulation module, and the state coding values ​​of the three half bridges are output to control the MOS tube switches of the three-phase inverter to control the motor; wherein, is the observed value of the rotor position angle.

[0041] The rotor speed observation value and the rotor position angle observation Output by the rotor position and speed observation module;

[0042] The voltage input to the rotor position and speed observation module is [ 1 − t a n d t a n d 1 ] [ u α u β ] ;

[0043] The current input to the rotor position and speed observation module is Current sampling value in the coordinate system and .

[0044] Compared with the existing model, the above model has the following technical effects:

[0045] (1) The motor analysis model proposed in the present invention, which uses equivalent magnetic induction parameters to account for the influence of iron loss, can take into account the influence of eddy current and hysteresis effects that cause iron loss on motor performance and control, is closer to the actual operating conditions of the motor, and has higher analysis and control accuracy;

[0046] (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 Axis and The degree of decoupling of the shaft current loop makes the surface-mounted permanent magnet synchronous motor have a faster step response and a more stable current waveform, thus improving the performance of vector control.

[0047] (3) Different from the traditional method of using resistance to equalize iron loss, the motor analysis model proposed in the present invention that uses equivalent magnetic induction parameters to account for the influence of iron loss is obtained by considering the relationship between magnetic circuit and circuit at the same time, making the introduction of iron loss more theoretically based. It is also simpler than the model that uses resistance to account for iron loss, and is similar in form to the traditional surface-mounted permanent magnet synchronous motor analysis model that does not consider the influence of iron loss. The traditional surface-mounted permanent magnet synchronous motor position sensorless control method can be used in the invented analysis model after simple improvement, and a position sensorless control system with higher control accuracy can be designed. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0049] Figure 1 It is a flow chart of a coordinate transformation based on vector magnetic circuit and a surface mounted permanent magnet synchronous motor analysis and control method of the present invention;

[0050] Figure 2 The invention is established Coordinate system diagram;

[0051] Figure 3 The invention is based on vector magnetic circuit and Block diagram of the position sensorless control method of the coordinate system;

[0052] Figure 4 It is a simulation effect diagram of the control method of the present invention;

[0053] Figure 5 This is a simulation effect diagram of position sensorless control when the rotation speed of the present invention is 1200r / min;

[0054] Figure 6 It is a simulation effect diagram of position sensorless control when the rotation speed of the present invention is 3000r / min. DETAILED DESCRIPTION

[0055] In combination with the appended Figure 1-3Based on the content of the present invention, a specific embodiment of a coordinate transformation based on a vector magnetic circuit and a surface-mounted permanent magnet synchronous motor analysis and control method is completed. Figure 4-6 The simulation results of the specific embodiments verify the effectiveness of the present invention. The described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] The present invention proposes a coordinate transformation based on a vector magnetic circuit and a surface mounted permanent magnet synchronous motor analysis and control method, comprising the following steps:

[0057] Step 1: Build a SPMSM Axis and Axis vector magnetic circuit model, the equivalent magnetic reactance With magnetic resistance The arc tangent value of the ratio is regarded as the iron loss angle, which is used to induce the influence of eddy current and hysteresis effect of iron loss on the stator flux and permanent magnet flux;

[0058] In the surface mounted permanent magnet synchronous motor Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance C are two vector magnetic circuit parameters, constructing Axis and Axis vector magnetic circuit model, using magnetic induction The magnetic induction C and magnetic capacitance C characterize the magnitude of the eddy current and hysteresis effect that cause iron loss; Both the magnetic flux and the magnetic capacitance C lag behind the magnetomotive force or current, so the equivalent magnetic induction parameter L can be used. eq Equivalent magnetic induction The combined effect of the magnetic capacitance C and the iron loss is taken into account; Axis and In the axial vector magnetic circuit model, the angle at which the magnetic flux lags behind the magnetomotive force or current is the iron loss angle. , which can be expressed as:

[0059] (1)

[0060] make:

[0061] (2)

[0062] say is the equivalent magnetic induction coefficient, which can be measured experimentally. In the present invention, the change of the equivalent magnetic induction coefficient is not considered, and the equivalent magnetic induction coefficient is considered to be a fixed parameter. Since the magnetic resistance can be expressed as , the iron loss angle of the surface-mounted permanent magnet synchronous motor can be expressed as:

[0063] (3)

[0064] In formula (1-3), for The magnetic induction in the coordinate system, C is Magnetic capacitance in the coordinate system, L eq for The equivalent magnetic induction in the coordinate system, R is The magnetic resistance in the coordinate system, for The inductance in the coordinate system, is the equivalent magnetic induction coefficient, is the iron loss angle, is the rotor electrical angular velocity, is the number of turns of the armature winding.

[0065] Step 2: Propose a Coordinate transformation and Coordinate system, such as Figure 2 As shown, Coordinate system lag Coordinate system a iron loss angle, based on the vector magnetic circuit and Coordinate system to establish the surface mounted permanent magnet synchronous motor analysis model, including vector magnetic circuit and Coordinate system flux equation and voltage equation;

[0066] Surface mounted permanent magnet synchronous motor Axis and The equivalent magnetic induction parameter L is introduced into the axis magnetic circuit equation eq , and then perform Parker transformation to obtain In the coordinate system Axis and Axis magnetic circuit equation:

[0067] (4)

[0068] In formula (4), and for The magnetomotive force in the coordinate system is and for Magnetic flux in the coordinate system, and for The current in the coordinate system is for Coordinate magnetic resistance, L eq for The equivalent magnetic induction in the coordinate system is, for The inductance in the coordinate system, is the permanent magnet flux, is the rotor electrical angular velocity, is the number of turns of the armature winding, is a differential operator;

[0069] When the motor is running stably, Axis and The shaft magnetic circuit is in a stable state, and further we can get:

[0070] (5)

[0071] Combining equations (3) and (5), we can get The flux equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0072] [ 1 − t a n d t a n d 1 ] [ ψ d ψ q ] = [ L s 0 0 L s ] [ i d i q ] + [ ψ f 0 ] (6)

[0073] Furthermore, multiply both sides of equation (6) by , we can get:

[0074] T d ′ [ ψ d ψ q ] = [ L s c o s d 0 0 L s c o s d ] [ i d i q ] + [ ψ f c o s d 0 ] (7)

[0075] In formula (7), T d ′ = [ c o s d − s i n d s i n d c o s d ] for The coordinate transformation matrix is The coordinate system rotates in the direction of lag by the iron loss angle , thus obtaining a new coordinate system, namely Coordinate system, Coordinate system lag Coordinate system horn;

[0076] In formula (5-7), and for Magnetic flux in the coordinate system, and for The current in the coordinate system, for The inductance in the coordinate system, is the permanent magnet flux, is the rotor electrical angular velocity;

[0077] Axis and Shaft voltage (flux) After transformation, we get Axis and Voltage (flux), further based on the vector magnetic circuit and The flux equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is:

[0078] [ ψ R ψ L ] = [ L s c o s d 0 0 L s c o s d ] [ i d i q ] + [ ψ f c o s d 0 ] (8)

[0079] The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is:

[0080] [ u R u L ] = [ R s 0 0 R s ] [ i R i L ] + [ p ψ R p ψ L ] + [ − oh ψ L oh ψ R ] (9)

[0081] Furthermore, according to the relationship [ i R i L ] = T d ′ [ i d i q ] And formula (8), use Axis and Shaft current replacement Axis and The shaft current Axis and Shaft magnetic link Axis and The shaft current is expressed as follows:

[0082] [ u R u L ] = [ R s c o s d + p L s c o s d − ( R s s i n d + oh L s c o s d ) R s s i n d + oh L s c o s d R s c o s d + p L s c o s d ] [ i d i q ] + [ 0 oh ψ f c o s d ] (10)

[0083] because , ignoring the According to formula (10), the vector magnetic circuit and The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is:

[0084] 1 cos d [ u R u L ] = [ R s + p L s − oh L s oh L s R s + p L s ] [ i d i q ] + [ 0 oh ψ f ] (11)

[0085] The voltage term on the left side of equation (10) is Expressed in the coordinate system, we can get The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0086] [ 1 − t a n d t a n d 1 ] [ u d u q ] = [ R s + p L s − oh L s oh L s R s + p L s ] [ i d i q ] + [ 0 oh ψ f ] (12)

[0087] Performing Clark inverse transformation on equation (12) yields The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0088] [ 1 − t a n d t a n d 1 ] [ u α u β ] = [ R s + p L s 0 0 R s + p L s ] [ i α i β ] + [ − oh ψ f s i n i oh ψ f c o s i ] (13)

[0089] In formula (8-13), and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The voltage in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, and for The current in the coordinate system, for The inductance in the coordinate system, for The resistance in the coordinate system, is the permanent magnet flux, is the iron loss angle, is the rotor electrical angular velocity, is the rotor position electrical angle, is the differential operator.

[0090] Step 3: Create a vector magnetic circuit and Position sensorless control method for surface mounted permanent magnet synchronous motor based on coordinate system.

[0091] According to the above-mentioned vector magnetic circuit and The surface mounted permanent magnet synchronous motor analysis model is established in the coordinate system, and a vector magnetic circuit and The coordinate system position sensorless control method is as follows:

[0092] The collaborative working process of each module is as follows: Figure 3 As shown, the three-phase current of the motor is sampled to obtain the sampled value , , ,Will , , After the Clark transformation module ( / )get Current sampling value in the coordinate system and , and then and After the Park transformation module ( / )get Current sampling value in the coordinate system and The error between the rotor speed and the speed setting value is obtained by the PI controller (PI) Axis and Shaft current setting value and ,Will and and and The error is input into two PI controllers (PI), and we get Voltage setting value in coordinate system and , based on the angle After the Park inverse transform module ( / )get Voltage setting value in coordinate system and ,use and The synthesized voltage space vector is input into the voltage space vector modulation module (SVPWM) for modulation, and the state coding values ​​of the three half-bridges are output to control the MOS tube switches of the three-phase inverter to control the motor. The rotor speed and rotor position angle used are provided by the rotor position and speed observation module (SMO);

[0093] The Park inverse transformation module in the present invention transforms the voltage in the RL coordinate system into the voltage in the α-β coordinate system. The angle input to the Park inverse transformation module is the rotor position angle observation value. Subtract iron loss angle ,Right now ;

[0094] The rotor position and speed observation module in the present invention is designed according to formula (13). The voltage information input to the rotor position and speed observation module (SMO) is: [ 1 − t a n d t a n d 1 ] [ u α u β ] .

[0095] The surface-mounted permanent magnet synchronous motor is simulated for position sensorless vector control. The motor speed is first adjusted to 1200r / min and the load is 7.7N·m, then the speed is adjusted to 3000r / min, and then the load is reduced by 2N·m. The step response speed and the stability of the current waveform are observed, and the effects of the control method of the present invention and the traditional vector control method are compared; the surface-mounted permanent magnet synchronous motor SPMSM is controlled to identify the rotor position and speed information at 1200r / min and 3000r / min respectively, and the position sensorless control based on the model of the present invention is compared with the traditional position sensorless control, and the errors between the observed rotor position and speed information and the actual values ​​are compared to verify the feasibility and effectiveness of the motor analysis model and control method proposed in the present invention. The parameters of the surface-mounted permanent magnet synchronous motor in the simulation are shown in the following table:

[0096]

[0097] like Figure 4 As shown, use Control, Control In the process of speed regulation and load reduction, the vector control proposed by the present invention The fluctuation is smaller, which improves the speed and stability of vector control in dealing with step response.

[0098] like Figure 5 and Figure 6 As shown in the figure, the position sensorless control based on the model of the present invention improves the rotor position observation accuracy compared with the traditional position sensorless control. The error is reduced by about 0.2 electrical degrees at 1200r / min and by about 0.7 electrical degrees at 3000r / min. Figure 5 and Figure 6 When the speed is high, the iron loss is also greater, which causes the traditional position sensorless control to produce a large identification error. The position sensorless control based on the model of the present invention has a better effect in improving the error.

[0099] The above describes the embodiments of the present invention in conjunction with the accompanying drawings, but does not limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solution of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A surface mounted permanent magnet synchronous motor analysis model, characterized in that: In the surface mounted permanent magnet synchronous motor SPMSM Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance C, construct Axis and Axis vector magnetic circuit model, the equivalent magnetic reactance With magnetic resistance The inverse tangent of the ratio is regarded as the iron loss angle of the surface mounted permanent magnet synchronous motor SPMSM ; propose Coordinate system and Coordinate transformation matrix ; Coordinate system lag Coordinate system iron loss angle ; Coordinate transformation matrix Will Coordinate system transformation to Coordinate system; Based on vector magnetic circuit and Coordinate system to establish the surface mounted permanent magnet synchronous motor analysis model, including vector magnetic circuit and Coordinate system flux equation and voltage equation.

2. According to claim 1, a surface mounted permanent magnet synchronous motor analysis model is characterized in that: The iron loss angle of the surface mounted permanent magnet synchronous motor SPMSM , expressed as; （1） make （2） is the equivalent magnetic induction coefficient; since the magnetic resistance is expressed as ; Then, the iron loss angle of the surface mounted permanent magnet synchronous motor SPMSM is expressed as: （3） in, for The magnetic induction in the coordinate system, C is Magnetic capacitance in the coordinate system, L eq for The equivalent magnetic induction in the coordinate system is, for The magnetic resistance in the coordinate system, for The inductance in the coordinate system, is the equivalent magnetic induction coefficient, is the iron loss angle, is the rotor electrical angular velocity, is the number of turns of the armature winding.

3. According to claim 2, a surface mounted permanent magnet synchronous motor analysis model is characterized in that: Coordinate transformation matrix , expressed as: 。 4. According to claim 3, a surface mounted permanent magnet synchronous motor analysis model is characterized in that: Get The flux equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is: （6） Multiply both sides of equation (6) by , The flux equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is also written as: （7） Axis and Axis flux Coordinate transformation matrix After transformation, we get Axis and Axis flux linkage; = ； Based on the vector magnetic circuit and The flux equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is: （8） 。 5. The surface mounted permanent magnet synchronous motor analysis model according to claim 4, characterized in that: The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is as follows: （9） According to the relationship And formula (8), use Axis and Shaft current replacement Axis and The shaft current Axis and Shaft magnetic link Axis and The shaft current is expressed as follows: （10） because , ignoring the According to formula (10), the vector magnetic circuit and The voltage equation of the surface-mounted permanent magnet synchronous motor in the coordinate system is written as: （11） in, and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, for The inductance in the coordinate system, for The resistance in the coordinate system, is the permanent magnet flux, is the iron loss angle, is the rotor electrical angular velocity, is the differential operator.

6. The surface mounted permanent magnet synchronous motor analysis model according to claim 5, characterized in that: The voltage term on the left side of equation (10) is Expressed in the coordinate system, we get The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is: （12） Perform Clark inverse transformation on equation (12) and we get The voltage equation of the surface-mounted permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is: （13） in, and for The current in the coordinate system, and for The voltage in the coordinate system, is the rotor position in electrical degrees.

7. A motor control method based on the surface mounted permanent magnet synchronous motor analysis model as claimed in claim 6, characterized in that: The steps include: Sample the three-phase current of the motor to obtain the sampled value , , ,Will , , After the Clark transformation module, we get Current sampling value in the coordinate system and , and then and After the Park transformation module, we get Current sampling value in the coordinate system and , rotor speed observation value With the set value The error is obtained by PI controller Axis and Shaft current setting value and ,Will and and and The error is input into two PI controllers respectively, and we get Voltage setting value in coordinate system and , through the Park inverse transform module, based on the angle Perform Park's inverse transform and Voltage setting value in coordinate system and Transformation Voltage setting value in coordinate system and ,use and The synthesized voltage space vector is modulated by the input voltage space vector modulation module, and the state coding values ​​of the three half bridges are output to control the MOS tube switches of the three-phase inverter to control the motor; wherein, is the observed value of the rotor position angle.

8. The motor control method according to claim 7, characterized in that: The rotor speed observation value comprises the following steps: and the rotor position angle observation Output by the rotor position and speed observation module; The voltage input to the rotor position and speed observation module is ; The current input to the rotor position and speed observation module is Current sampling value in the coordinate system and .

Images