Vector magnetic circuit coordinate transformation and embedded permanent magnet motor analysis and control method considering salient pole effect

Abstract

The invention discloses a vector magnetic circuit coordinate transformation and embedded permanent magnet motor analysis and control method considering a salient pole effect, which comprises the following steps of: firstly, establishing a d-axis vector magnetic circuit model and a q-axis vector magnetic circuit model of an embedded permanent magnet motor, and regarding an arc tangent value of a ratio of equivalent magnetic inductive reactance to magnetic resistance of a d-axis magnetic circuit or a q-axis magnetic circuit as an iron loss angle of the d-axis magnetic circuit or the q-axis magnetic circuit; d-axis and q-axis iron loss angles are used to consider the influence of iron loss and the salient pole effect on motor performance and control thereof, and R-L coordinate transformation considering the salient pole effect and an R-L coordinate system considering the salient pole effect are provided; and then, establishing a flux linkage equation and a voltage equation based on a vector magnetic circuit and an R-L coordinate system considering a salient pole effect, and establishing a sensorless control method based on the provided analysis model. The method provided by the invention can fully consider the influence of the iron loss and the salient pole effect on the motor performance and the 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 permanent magnet synchronous motor control, and in particular relates to a vector magnetic circuit coordinate transformation and an embedded permanent magnet motor analysis and control method taking salient pole effect into consideration. Background Art

[0002] Interior permanent magnet synchronous motor (IPMSM) has the advantages of high power density, wide speed regulation range, high working efficiency, etc. It has broad application prospects in the industrial field. In recent years, it has been widely used in rail transportation, household appliances, electric vehicles and other fields. The performance of permanent magnet synchronous motor is not only affected by the structure of the motor body, but also by the control algorithm. Among them, vector control is one of the most common control methods of permanent magnet synchronous motor.

[0003] To achieve high-performance control of permanent magnet synchronous motors, accurate rotor position and speed information is essential. Usually, rotor position and speed information can be obtained through position sensors, such as resolvers, absolute position encoders, etc. However, position sensors also bring some problems to the entire traction drive system, such as increased system cost, reduced system reliability caused by position sensor failure, and increased installation volume of traction motors. In order to solve the problems caused by position sensors, position sensorless control has received more and more attention at home and abroad in recent years. According to the current research status, permanent magnet synchronous motor position sensorless control is mainly divided into methods based on salient pole characteristics applied in the zero-low speed range and methods based on fundamental wave models applied in the medium and high speed range. Usually, methods based on fundamental wave models can obtain satisfactory control performance in the medium and high speed operation range. Methods based on fundamental wave models mainly estimate the rotor position and speed information by estimating the back electromotive force component. Iron loss is inevitable when the motor is running. However, most of the research on position sensorless control of permanent magnet synchronous motors is carried out without considering iron loss. When the motor is running at medium and high speeds, the iron loss is large due to the high speed, and the motor fundamental wave model is required. The use of traditional motor models that do not consider iron loss will affect the performance of the position sensorless control system. Therefore, it is very important to establish a more accurate permanent magnet synchronous motor model that takes iron loss into account.

[0004] The Southeast University team proposed the magnetic induction, magnetic capacitance, vector magnetic circuit theory and magneto-electric power law, which provided a new method for considering the iron loss of permanent magnet synchronous motors, 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. They introduced magnetic induction into the permanent magnet synchronous motor model to consider the influence of eddy current reaction on the permanent magnet magnetic flux and the stator magnetic flux excited by the armature current, and derived a new permanent magnet synchronous motor model based on the vector magnetic circuit theory.

[0005] For embedded permanent magnet synchronous motors, due to their Axis and The shaft inductance is asymmetric, and the basic mathematical model cannot be used to directly estimate the rotor position and speed. Therefore, some scholars have proposed the concept of extended back-EMF, and estimated the rotor position and speed by estimating the extended back-EMF. In the analysis model of embedded permanent magnet synchronous motor based on vector magnetic circuit theory, the introduction of coupling terms makes the extended back-EMF more complicated. The method of constructing observers is used for estimation, such as disturbance observers, full-order observers, sliding mode observers, etc. Among them, the sliding mode observer, as a nonlinear robust control strategy, has good robustness to the uncertainty and disturbance of the system model, has broad application prospects, and has gradually been applied to position sensorless control. Summary of the invention

[0006] The purpose of the present invention is to consider the iron loss of an embedded permanent magnet synchronous motor, use coordinate transformation to reflect the influence of iron loss on the motor, improve the analysis model of the embedded permanent magnet synchronous motor based on the vector magnetic circuit, realize the position sensorless control of the embedded permanent magnet synchronous motor considering the iron loss when the motor is running at medium and high speeds, and improve the position sensorless control accuracy of the embedded permanent magnet synchronous motor.

[0007] The present invention proposes a vector magnetic circuit coordinate transformation and embedded permanent magnet synchronous motor analysis model considering the salient pole effect: Axis and Axis vector magnetic circuit model, considering an embedded permanent magnet synchronous motor Axis and The axis magnetic resistance is different, and the equivalent magnetic inductive reactance is The inverse tangent of the axial reluctance ratio is regarded as Shaft iron loss angle , the equivalent magnetic inductive reactance and The inverse tangent of the axial reluctance ratio is regarded as Shaft iron loss angle ,use Axis and The shaft iron loss angle is used to characterize the influence of iron loss and salient pole effect on stator flux and permanent magnet flux;

[0008] A method considering the saliency effect is proposed. Coordinate transformation and consideration of saliency effect Coordinate system, considering the saliency effect Coordinate system Axis and Axis hysteresis Coordinate system Axis and axis and , based on vector magnetic circuit and considering salient pole effect The embedded permanent magnet motor analysis model is established in the coordinate system, including the vector magnetic circuit and the salient pole effect. Coordinate system flux equation and voltage equation;

[0009] Furthermore, the embedded permanent magnet synchronous motor Axis and The axis vector magnetic circuit model refers to the embedded permanent magnet synchronous motor IPMSM Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance ; Using magnetic induction and magnetic capacitance Characterize iron loss; magnetic induction and magnetic capacitance The magnetic flux lags behind the magnetomotive force or current, so the equivalent magnetic induction parameter Equivalent magnetic induction and magnetic capacitance The joint effect.

[0010] Furthermore, the active power loss caused by the magnetic induction element corresponds to the eddy current loss in the magnetic circuit, and the active power loss caused by the magnetic capacitance element corresponds to the hysteresis loss in the magnetic circuit.

[0011] Furthermore, Shaft iron loss angle and Shaft iron loss angle , respectively expressed as follows: (1) (2) make: (3) say is the equivalent magnetic induction coefficient; because Axis and The magnetic reluctance of the axis is expressed as and ; Then, the embedded permanent magnet synchronous motor IPMSM Iron loss angle of the shaft and Iron loss angle of the shaft It is expressed as: (4) (5) for The magnetic induction in the coordinate system, for The magnetic capacitance in the coordinate system, for The reluctance of the axis, for The reluctance of the shaft, for The inductance of the shaft, for The inductance of the shaft, for Iron loss angle of the shaft, for Iron loss angle of the shaft, is the rotor electrical angular velocity, is the number of turns of the armature winding.

[0012] Furthermore, by introducing the equivalent magnetic induction parameter into the magnetic circuit of the embedded permanent magnet motor, we can obtain The flux equation of the embedded permanent magnet motor based on the vector magnetic circuit in coordinates: (8) The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system: (9) Multiply both sides of the above equation by the matrix , and because , ,neglect , , and ; have to The voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system: (11) get The voltage equation of the embedded permanent magnet motor based on the vector magnetic circuit in the coordinate system is: (12) Among them, the back electromotive force for: (13) In the formula, and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, and is the voltage in the α-β coordinate system, and is the current in the α-β coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the differential operator.

[0013] Furthermore, considering the saliency effect The coordinate transformation satisfies that the amplitude, phase and angular velocity of the synthetic phasor remain unchanged before and after the transformation, which can be expressed as: (14) in, is the synthetic phase, The synthetic phase Axis component, The synthetic phase Axis component, The synthetic phase Axis component, The synthetic phase Axis component, is the angular velocity of rotation of the phasor; have to Coordinate system and consideration of saliency effect Coordinate transformation relationship of coordinate system: (15) in, To consider the saliency effect The coordinate transformation matrix is Axis and The direction of axial hysteresis is respectively the iron loss angle and ,make Coordinate system transformation to Coordinate system.

[0014] Furthermore, it is characterized in that The flux term in the flux equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is transformed to In the coordinate system, based on the vector magnetic circuit and considering the salient pole effect, The flux equation of the embedded permanent magnet synchronous motor in the coordinate system is: (16) Will The flux term in the voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit is transformed into In the coordinate system, due to the small iron loss angle, , , , based on the vector magnetic circuit and considering the salient pole effect The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is: (17) neglect and , based on the vector magnetic circuit and considering the salient pole effect The simplified form of the voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is: (18) In the formula, 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 of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the differential operator.

[0015] Based on the embedded permanent magnet synchronous motor analysis model of the present invention, the present invention also proposes a motor control method, comprising the following steps: The three-phase current of the motor is sampled to obtain , , ,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 ,calculate Axis and Shaft current sampling value and With the set value and The error is input into two PI controllers respectively, and we get Voltage in coordinate system and , by considering the saliency effect The coordinate transformation module obtains Voltage in coordinate system and , and then through the Park inverse transformation module, based on the rotor position angle observation value Perform Park's inverse transform to obtain Voltage in coordinate system and ,use and The synthesized voltage space vector is input into the voltage space vector modulation module 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.

[0016] Furthermore, the rotor speed observation value is obtained through the rotor position and speed observation module and the rotor position angle observation ; The rotor position and speed observation module includes a sliding mode observer, a low-pass filter and a phase-locked loop; Assume the back electromotive force: ,in: (20) The sliding mode observer is designed according to formula (12). The input of the sliding mode observer is and , after low-pass filtering and phase and amplitude compensation, the back electromotive force observation value is obtained , the rotor position information is extracted as follows: (twenty one) Rotor position angle observation It is expressed as: (twenty two) The inverse tangent is calculated by the phase-locked loop, and the rotor angular velocity observation value It is expressed as: (twenty three) Rotor speed observation It is expressed as: (twenty four) In formula (20-24), and for The motor state measurement value in the coordinate system, and is the observed value of the back electromotive force in the two-phase stationary coordinate system, and is the voltage of the two-phase stationary coordinate system, and is the current in the two-phase stationary coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the resistance of the armature winding, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, is the rotor electrical angular velocity, is the observed value of the rotor electrical angular velocity, is the rotor position electrical angle, is the observed value of the rotor position angle, is the differential operator, is the pole pair number.

[0017] Furthermore, the consideration of the salient pole effect The coordinate transformation module is to transform Axis and The shaft voltage is converted to Axis and The shaft voltage, input-output relationship is expressed as: (19) In formula (19), and To consider the saliency effect The input and output matrices of the coordinate transformation module, To consider the saliency effect Coordinate transformation matrix The inverse matrix of .

[0018] Compared with the existing model, the model of the present invention has the following technical effects:

[0019] (1) The embedded permanent magnet synchronous motor analysis model considering iron loss proposed in the present invention is closer to the actual embedded permanent magnet synchronous motor than the model ignoring iron loss, and has higher control accuracy;

[0020] (2) Different from the traditional method of using resistance to equate iron loss, the present invention is based on the vector magnetic circuit theory and takes into account the relationship between the magnetic circuit and the circuit. It proposes an analysis model of an embedded permanent magnet synchronous motor based on the vector magnetic circuit and the influence of iron loss.

[0021] (3) According to the voltage equation design vector control of the embedded permanent magnet synchronous motor based on the vector magnetic circuit coordinate transformation proposed by the present invention, Axis current loop and The shaft current loop decoupling effect is better, which makes the embedded permanent magnet synchronous motor step response faster and the current waveform more stable, which is more conducive to the vector control of the embedded permanent magnet synchronous motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] 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.

[0023] Figure 1 It is a flow chart of a vector magnetic circuit coordinate transformation and embedded permanent magnet motor analysis and control method considering salient pole effect of the present invention;

[0024] Figure 2 A schematic diagram of a coordinate system established in the present invention;

[0025] Figure 3 The invention is based on the vector magnetic circuit and considers the salient pole effect. Block diagram of the position sensorless control method for an embedded permanent magnet motor in a coordinate system;

[0026] Figure 4 This is a simulation effect diagram of the control method of the present invention;

[0027] Figure 5 This is a simulation effect diagram of the position sensorless control when the rotation speed of the present invention is 500r / min;

[0028] Figure 6 This is a simulation effect diagram of position sensorless control when the rotation speed of the present invention is 1000r / min. DETAILED DESCRIPTION

[0029] Combined with the present invention Figure 1-3 Based on the content of the present invention, a specific embodiment of a vector magnetic circuit coordinate transformation and an embedded permanent magnet synchronous motor analysis and control method considering the salient pole effect 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.

[0030] The vector magnetic circuit coordinate transformation and embedded permanent magnet synchronous motor analysis and control method considering the salient pole effect of the present invention comprises the following steps:

[0031] Step 1: Build the embedded permanent magnet motor Axis and Axis vector magnetic circuit model, considering an embedded permanent magnet synchronous motor Axis and The axis magnetic resistance is different, and the equivalent magnetic inductive reactance is The inverse tangent of the axial reluctance ratio is regarded as Shaft iron loss angle , the equivalent magnetic inductive reactance and The inverse tangent of the axial reluctance ratio is regarded as Shaft iron loss angle ,use Axis and The shaft iron loss angle is used to characterize the influence of iron loss and salient pole effect on stator flux and permanent magnet flux;

[0032] Embedded permanent magnet synchronous motor Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance Two vector magnetic circuit parameters, construct Axis and Axis vector magnetic circuit model, using magnetic induction and magnetic capacitance Characterizes the iron loss. 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. and magnetic capacitance The magnetic flux lags behind the magnetomotive force or current, so the equivalent magnetic induction parameter can be used Equivalent magnetic induction and magnetic capacitance The combined effect of iron loss is taken into account; Axis and In the axial vector magnetic circuit model, Axis and The axis magnetic circuit is different, that is, the magnetic resistance is different. Axis and The iron loss angle produced by the shaft is also different. The shaft flux lags behind The angle of the shaft magnetomotive force or current is the iron loss angle , iron loss angle It can be expressed as the equivalent magnetic inductive reactance and The inverse tangent of the axial reluctance ratio; The shaft flux lags behind The angle of the shaft magnetomotive force or current is the iron loss angle , iron loss angle It can be expressed as the equivalent magnetic inductive reactance and The inverse tangent value of the axial reluctance ratio is expressed as follows:

[0033] (1)

[0034] (2)

[0035] make:

[0036] (3)

[0037] 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. Axis and The axial reluctance can be expressed as and , further, embedded permanent magnet synchronous motor Iron loss angle of the shaft and Iron loss angle of the shaft It can be expressed as:

[0038] (4)

[0039] (5)

[0040] In formula (1-5), for The magnetic induction in the coordinate system, for The magnetic capacitance in the coordinate system, for The reluctance of the shaft, for The reluctance of the shaft, for The inductance of the shaft, for The inductance of the shaft, for Iron loss angle of the shaft, for Iron loss angle of the shaft, is the rotor electrical angular velocity, is the number of turns of the armature winding.

[0041] Step 2: Propose a method that takes into account the saliency effect Coordinate transformation and consideration of saliency effect Coordinate system, considering the saliency effect Coordinate system Axis and Axis hysteresis Coordinate system Axis and axis and , based on vector magnetic circuit and considering salient pole effect The embedded permanent magnet motor analysis model is established in the coordinate system, including the vector magnetic circuit and the salient pole effect. Coordinate system flux equation and voltage equation;

[0042] Introducing equivalent magnetic induction parameters into magnetic circuit equations of embedded permanent magnet synchronous motors , based on the vector magnetic circuit theory, and then performing Parker transformation, we get The magnetic circuit equation based on the vector magnetic circuit in the coordinate system,

[0043] (6)

[0044] In formula (6), 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 The equivalent magnetic induction in the coordinate system is, for The reluctance of the shaft, for The reluctance of the shaft, for The inductance of the shaft, for The inductance of the shaft, is the permanent magnet flux, is the rotor electrical angular velocity, is the number of turns of the armature winding, is a differential operator;

[0045] When the motor is running stably, Axis and The shaft magnetic circuit is in a stable state, and further we can get: (7)

[0046] Combining equations (4), (5) and (7), we get The flux equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0047] (8)

[0048] The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system:

[0049] [ u d u q ] = [ R s 0 0 R s ] [ i d i q ] + [ p ψ d p ψ q ] + [ − oh ψ q oh ψ d ] (9)

[0050] Multiply both sides of the above equation by the matrix [ 1 − t a n d d t a n d q 1 ] ,have to:

[0051] [ 1 − t a n d d t a n d q 1 ] [ u d u q ] = [ R s + oh L d ( t a n d q − t a n d d ) + p L d − t a n d d R s − oh L q ( t a n 2 d d + 1 ) t a n d q R s + oh L d ( t a n 2 d q + 1 ) R s − oh L q ( t a n d q − t a n d d ) + p L q ] [ i d i q ] + [ oops f ( t a n d q − t a n d d ) oops f ( t a n 2 d q + 1 ) ] (10)

[0052] In formula (10), , , can be ignored , , and , we can conclude The voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0053] [ 1 − t a n d d t a n d q 1 ] [ u d u q ] = [ R s + oh L d ( t a n d q − t a n d d ) + p L d − oh L q oh L d R s − oh L q ( t a n d q − t a n d d ) + p L q ] [ i d i q ] + [ oops f ( t a n d q − t a n d d ) oops f ] (11)

[0054] Further, we get The voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is:

[0055] [ 1 − t a n d d t a n d d 1 ] [ u α u β ] = [ R s + p L d − oh ( L q − L d ) oh ( L q − L d ) R s + p L d ] [ i α i β ] + [ e α e β ] (12)

[0056] In formula (12), the back electromotive force [ e α e β ] for:

[0057] [ e α e β ] = [ cos i − sin i sin i cos i ] ( [ 0 oops f ] + ( L q − L d ) [ oh 2 kL d i d + oh 2 k ψ f pi q − oh i d − oh 2 kL q i q − oh ku d ] ) (13)

[0058] In formulas (7)-(13), and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, and is the voltage of the two-phase stationary coordinate system, and is the current in the two-phase stationary coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the rotor position electrical angle, is the differential operator.

[0059] Due to the saliency effect, Axis and The axis magnetic circuit is different, the magnetic resistance is different, Axis and The iron loss angle produced by the shaft is also different, such as Figure 2 As shown in Figure 2, considering the saliency effect In the coordinate system, Axis hysteresis Shaft iron loss angle , Axis hysteresis Shaft iron loss angle ;

[0060] Considering the saliency effect The coordinate transformation needs to ensure that the amplitude, phase and angular velocity of the synthetic phasor remain unchanged before and after the transformation, which can be expressed as:

[0061] (14)

[0062] In formula (14), is the synthetic phase, The synthetic phase Axis component, The synthetic phase Axis component, The synthetic phase Axis component, The synthetic phase Axis component, is the angular velocity of rotation of the phasor;

[0063] Available Coordinate system and consideration of saliency effect Coordinate transformation relationship of coordinate system:

[0064] [ ψ R ψ L ] = 1 cos ( d q − d d ) [ cos d q − sin d q sin d d cos d d ] [ ψ d ψ q ] (15)

[0065] In formula (15), T d ′ = 1 cos ( d q − d d ) [ cos d q − sin d q sin d d cos d d ] To consider the saliency effect The coordinate transformation matrix is Axis and The direction of axial hysteresis is respectively the iron loss angle and ,make Coordinate system transformation to Coordinate system;

[0066] Combining equations (8) and (15), we can obtain the equation based on the vector magnetic circuit and considering the salient pole effect: The flux equation of the embedded permanent magnet synchronous motor in the coordinate system is:

[0067] (16)

[0068] The voltage term on the left side of equation (11) is transformed by the coordinate system matrix Transform to In the coordinate system, due to the small iron loss angle, it can be considered , , , based on the vector magnetic circuit and considering the salient pole effect, The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is:

[0069] (17)

[0070] If ignored and , based on the vector magnetic circuit and considering the salient pole effect, The simplified form of the voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is:

[0071] (18)

[0072] In formulas (15)-(18), 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 current in the coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the differential operator.

[0073] Step 3: Establish a vector magnetic circuit and consider the salient pole effect Position sensorless control method for embedded permanent magnet motor in coordinate system; Based on the vector magnetic circuit and considering the salient pole effect The embedded permanent magnet motor analysis model is established in the coordinate system, and the vector magnetic circuit and salient pole effect are considered. A position sensorless control method for an embedded permanent magnet motor based on a coordinate system, comprising: a speed loop, Axis current loop, Axis current loop; specific modules include: PI controller, voltage space vector modulation module SVPWM, Clark transformation module 、Clark inverse transform module , Park Transform Module , Park inverse transform module , considering the salient pole effect Coordinate transformation module and rotor position and speed observation module SMO; 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 , , ,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 ,calculate Axis and Shaft current sampling value and With the set value and The error is input into two PI controllers respectively, and we get Voltage in coordinate system and , by considering the saliency effect The coordinate transformation module obtains Voltage in coordinate system and , and then through the Park inverse transformation module, based on the rotor position angle observation value Perform Park's inverse transform to obtain Voltage in coordinate system and ,use and The synthesized voltage space vector is input into the voltage space vector modulation module 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.

[0074] Considering the saliency effect The coordinate transformation module is to transform Axis and The shaft voltage is converted to Axis and The shaft voltage, input-output relationship is expressed as: (19) In formula (19), and To consider the saliency effect The input and output matrices of the coordinate transformation module, To consider the saliency effect Coordinate transformation matrix The inverse matrix of .

[0075] The rotor position and speed observation module in the present invention includes a sliding mode observer, a low-pass filter and a phase-locked loop; According to formula (13), the back electromotive force is: ,in: (20) The sliding mode observer is designed according to formula (12). The input of the sliding mode observer is and , after low-pass filtering and phase and amplitude compensation, the back electromotive force observation value is obtained , the rotor position information is extracted as follows: (twenty one) Rotor position angle observation It is expressed as: (twenty two) The inverse tangent is calculated by the phase-locked loop, and the rotor angular velocity observation value It is expressed as: (twenty three) Rotor speed observation It is expressed as: (twenty four) In formula (20-24), and for The motor state measurement value in the coordinate system, and is the observed value of the back electromotive force in the two-phase stationary coordinate system, and is the voltage of the two-phase stationary coordinate system, and is the current in the two-phase stationary coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the resistance of the armature winding, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, is the rotor electrical angular velocity, is the observed value of the rotor electrical angular velocity, is the rotor position electrical angle, is the observed value of the rotor position angle, is the differential operator, is the pole pair number.

[0076] The embedded permanent magnet synchronous motor is simulated by position sensorless vector control. The motor speed is first adjusted to 500r / min and the load is 20N·m. Then the speed is adjusted to 1000r / min and the load is reduced to 8N·m. The step response speed and the stability of the current waveform are observed. Figure 4 As shown, the effects of the vector control proposed in the present invention are compared with those of traditional vector control.

[0077] like Figure 5 and Figure 6 , respectively control the embedded permanent magnet synchronous motor at 500r / min and 1000r / min to identify the rotor position and speed information, compare the position sensorless control based on the proposed model with the traditional position sensorless control, compare the errors between the observed rotor position and speed information and the actual values, and verify the feasibility and effectiveness of the motor analysis model and control method proposed in the present invention. The parameters of the embedded permanent magnet synchronous motor in the simulation are shown in the following table:

[0078] 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.

[0079] like Figure 5 and Figure 6 As shown in the figure, the position sensorless control based on the proposed model improves the rotor position observation accuracy compared with the traditional position sensorless control. The error is reduced by about 0.25 electrical degrees at 500r / min and by about 0.8 electrical degrees at 1000r / 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 proposed model is also more effective in improving the error.

[0080] The above describes the embodiments of the present invention in conjunction with the figures, 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. An analysis model of an embedded permanent magnet synchronous motor based on a vector magnetic circuit, characterized in that: Firstly, the embedded permanent magnet synchronous motor is established Axis and Axis vector magnetic circuit model, The shaft flux lags behind The angle of the axial magnetomotive force or current is recorded as Shaft iron loss angle , Shaft iron loss angle Equivalent magnetic inductive reactance and The inverse tangent of the axis reluctance ratio; where, is the rotor electrical angular velocity, represents the equivalent magnetic induction parameter; The shaft flux lags behind The angle of the axial magnetomotive force or current is recorded as Shaft iron loss angle , Shaft iron loss angle Equivalent magnetic inductive reactance and The inverse tangent of the axial reluctance ratio; The saliency effect is considered Coordinate transformation and consideration of saliency effect Coordinate system, the salient pole effect is considered R axis hysteresis of the coordinate system Coordinate system axis , the consideration of salient pole effect Coordinate system Axis hysteresis Coordinate system axis ; Based on vector magnetic circuit and considering salient pole effect The embedded permanent magnet motor analysis model is established in the coordinate system, including the vector magnetic circuit and the salient pole effect. Coordinate system flux equation and voltage equation.

2. According to claim 1, an analysis model of an embedded permanent magnet synchronous motor based on a vector magnetic circuit is characterized in that: The embedded permanent magnet synchronous motor Axis and The axis vector magnetic circuit model refers to the embedded permanent magnet synchronous motor IPMSM Axis and Introducing magnetic induction into the shaft magnetic circuit model and magnetic capacitance ; Using magnetic induction and magnetic capacitance Characterize iron loss; Magnetic induction and magnetic capacitance Both cause the magnetic flux to lag behind the magnetomotive force or current.

3. According to claim 2, an analysis model of an embedded permanent magnet synchronous motor based on a vector magnetic circuit is characterized in that: The active power loss caused by the magnetic induction element corresponds to the eddy current loss in the magnetic circuit, and the active power loss caused by the magnetic capacitance element corresponds to the hysteresis loss in the magnetic circuit.

4. According to claim 2, an analysis model of an embedded permanent magnet synchronous motor based on a vector magnetic circuit is characterized in that: Shaft iron loss angle and Shaft iron loss angle , respectively expressed as follows: （1） （2） make: （3） say is the equivalent magnetic induction coefficient; because Axis and The magnetic reluctance of the axis is expressed as and ; Then, the embedded permanent magnet synchronous motor IPMSM Iron loss angle of the shaft and Iron loss angle of the shaft It is expressed as: （4） （5） for The magnetic induction in the coordinate system, for The magnetic capacitance in the coordinate system, for The reluctance of the axis, for The reluctance of the axis, for The inductance of the shaft, for The inductance of the shaft, for Iron loss angle of the shaft, for Iron loss angle of the shaft, is the rotor electrical angular velocity, is the number of turns of the armature winding.

5. The embedded permanent magnet synchronous motor analysis model based on vector magnetic circuit according to claim 3 is characterized in that: Introducing equivalent magnetic induction parameters into the magnetic circuit of the embedded permanent magnet motor, we get The flux equation of the embedded permanent magnet motor based on the vector magnetic circuit in coordinates: （8） The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system: （9） Multiply both sides of the above equation by the matrix , and because , ,neglect , , and ; have to The voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system: （11） get The voltage equation of the embedded permanent magnet motor based on the vector magnetic circuit in the coordinate system is: （12） Among them, the back electromotive force for: （13） In the formula, and for Magnetic flux in the coordinate system, and for The voltage in the coordinate system, and for The current in the coordinate system, and is the voltage in the α-β coordinate system, and is the current in the α-β coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the differential operator.

6. The embedded permanent magnet synchronous motor analysis model based on vector magnetic circuit according to claim 5 is characterized in that: Considering the saliency effect The coordinate transformation satisfies that the amplitude, phase and angular velocity of the synthetic phasor remain unchanged before and after the transformation, which can be expressed as: （14） in, is the synthetic phase, is the R-axis component of the synthetic phase, The synthetic phase Axis component, The synthetic phase Axis component, The synthetic phase Axis component, is the angular velocity of rotation of the phasor; have to Coordinate system and consideration of saliency effect Coordinate transformation relationship of coordinate system: （15） in, To consider the saliency effect The coordinate transformation matrix is Axis and The direction of axial hysteresis is respectively the iron loss angle and ,make Coordinate system transformation to Coordinate system.

7. The embedded permanent magnet synchronous motor analysis model based on vector magnetic circuit according to claim 6 is characterized in that: Will The flux term in the flux equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit in the coordinate system is transformed to In the coordinate system, based on the vector magnetic circuit and considering the salient pole effect, The flux equation of the embedded permanent magnet synchronous motor in the coordinate system is: （16） Will The flux term in the voltage equation of the embedded permanent magnet synchronous motor based on the vector magnetic circuit is transformed into In the coordinate system, due to the small iron loss angle, , , , based on the vector magnetic circuit and considering the salient pole effect The voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is: （17） neglect and , based on the vector magnetic circuit and considering the salient pole effect The simplified form of the voltage equation of the embedded permanent magnet synchronous motor in the coordinate system is: （18） In the formula, 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 of the shaft, for The inductance of the shaft, is the armature winding resistance, is the permanent magnet flux, for Shaft iron loss angle, for Shaft iron loss angle, is the rotor electrical angular velocity, is the differential operator.

8. A motor control method based on the embedded permanent magnet synchronous motor analysis model of claim 7, characterized in that: The steps include: The three-phase current of the motor is sampled to obtain , , ,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 ,calculate Axis and Shaft current sampling value and With the set value and The error is input into two PI controllers respectively, and we get Voltage in coordinate system and , by considering the saliency effect The coordinate transformation module obtains Voltage in coordinate system and , and then through the Park inverse transformation module, based on the rotor position angle observation value Perform Park's inverse transform to obtain Voltage in coordinate system and ,use and The synthesized voltage space vector is input into the voltage space vector modulation module 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.

9. The motor control method according to claim 8, characterized in that: Obtain rotor speed observation value through rotor position and speed observation module and the rotor position angle observation ; The rotor position and speed observation module includes a sliding mode observer, a low-pass filter and a phase-locked loop; Assume the back electromotive force: ,in: （20） The sliding mode observer is designed according to formula (12). The input of the sliding mode observer is and , after low-pass filtering and phase and amplitude compensation, the back electromotive force observation value is obtained , the rotor position information is extracted as follows: （21） Rotor position angle observation It is expressed as: （22） The inverse tangent is calculated by the phase-locked loop, and the rotor angular velocity observation value It is expressed as: （23） Rotor speed observation It is expressed as: （24） In formula (20-24), and for The motor state measurement value in the coordinate system, and is the observed value of the back electromotive force in the two-phase stationary coordinate system, and is the voltage of the two-phase stationary coordinate system, and is the current in the two-phase stationary coordinate system, for The inductance of the shaft, for The inductance of the shaft, is the resistance of the armature winding, is the permanent magnet flux, is the equivalent magnetic induction coefficient, for Shaft iron loss angle, is the rotor electrical angular velocity, is the observed value of the rotor electrical angular velocity, is the rotor position electrical angle, is the observed value of the rotor position angle, is the differential operator, is the pole pair number.

10. The motor control method according to claim 8, characterized in that: The consideration of the saliency effect The coordinate transformation module is to transform the R axis and The shaft voltage is converted to Axis and The shaft voltage, input-output relationship is expressed as: （19） In formula (19), and To consider the saliency effect The input and output matrices of the coordinate transformation module, To consider the saliency effect Coordinate transformation matrix The inverse matrix of .

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