A kind of high frequency square wave voltage injection permanent magnet synchronous motor of optimal injector angle is passed without position
Sensor control method
Technical field
The invention belongs to the technical fields of permanent magnet synchronous motor control, are related to a kind of high frequency square wave voltage of optimal injector angle
Inject permanent magnet synchronous motor method for controlling position-less sensor.
Background technique
Permanent magnet synchronous motor is because of the advantages that its structure is simple, high-efficient and power density is big, in recent years in electric car, family
The fields such as electrical appliance, industrial automation are in occupation of critical role.Permanent magnet synchronous motor vector control technology is usually passed with mechanical
Sensor (such as photoelectric encoder, rotary transformer) detects rotor-position, but using sensor bring system cost increase,
The problems such as volume weight increases, reduces vulnerable to interference, reliability.Therefore, permanent magnet synchronous motor position-sensor-free (position self-test
Survey) control method is concerned, there is very high engineering practical value and research significance.
High Frequency Injection due to it independent of the parameter of electric machine, without counter electromotive force information the features such as and be widely used in
Position Sensorless Control under low speed and static operating condition.However, due to injecting additional high frequency voltage (electric current) signal, it will right
System causes various adverse effects, such as loss increases, electromagnetic noise is significant.Especially high frequency electrocardiography will generate larger
Current ripples generate biggish pulsation so as to cause torque.
Summary of the invention
In order to solve the deficiency referred in above-mentioned background technique, the present invention proposes a kind of high frequency using optimal implant angle
Square wave voltage signal injects permanent magnet synchronous motor Sensorless Control Technique.Due to conventional estimation d axis high-frequency electrical pressure injection
Enter in method, generated high-frequency current vector may cause biggish torque pulsation in internal permanent magnet synchronous motor.Cause
This, by changing the direction of injection high frequency voltage vector, in internal permanent magnet synchronous motor torque capacity electric current ratio (Maximum
Torque per Ampere, MTPA) under vector controlled, make its corresponding high-frequency current vector along the tangent line of torque isopleth
Direction can imitate reduction torque pulsation.
The technical solution proposed to solve the above-mentioned problems are as follows:
A kind of high frequency square wave voltage injection permanent magnet synchronous motor method for controlling position-less sensor of optimal injector angle, it is described
Control method the following steps are included:
Step 1, it is as follows that permanent magnet synchronous motor mathematical model, process under high frequency square wave voltage signal are established:
1.1, in dq two-phase synchronous rotating frame, the voltage status equation of internal permanent magnet synchronous motor IPMSM is used
The form of matrix is expressed as follows
In formula,Stator voltage and current phasor, R respectively under rotor reference systemsFor stator
Resistance, Ld、LqFor d, q axle inductance, ωeFor electrical angular speed, ψfFor PM rotor magnetic linkage amplitude;Subscript r indicates armature spindle
System;
1.2, the high-frequency voltage signal by frequency much larger than fundamental frequency injects IPMSM, and in the lower situation of revolving speed,
The voltage and back-emf voltage of stator resistance can be ignored, therefore, the high-frequency resistance model of IPMSM can be expressed simply as
Following pure inductance model:
In formula,High frequency voltage, current component respectively on d, q axis;Subscript h indicates high frequency content;
1.3, di/dt can be approximated to be Δ i/ Δ t in a switch periods, and formula (2) is rewritten as
In formula, Δ T indicates a switch periods, and (3) formula is motor discrete models under high-frequency square-wave signal;
Step 2, it calculates varied angle high frequency square wave and is infused in estimation rotor axial system component of voltage, process is as follows:
2.1, any synchronous rotating frame kl is defined, injects high frequency square wave voltage signal in its k axis
In formula,For the high frequency voltage for being injected separately into k axis and l axis in any synchronous rotating frame, VhFor note
Enter voltage magnitude, n indicates sampling sequence number;
2.2, the high-frequency voltage signal for injecting kl shafting is transformed into estimation synchronous rotating frameIt is interior, it obtains estimation and sits
Mark is interior high-frequency voltage signal
In formula,Respectively estimate in synchronous rotating frameAxis andHigh-frequency voltage signal, γ be injection
The synchronous rotary kl shafting of high-frequency signal and estimationAngle between shafting, i.e.,θkIndicate injection coordinate system and
Angle between rest frame, T (θ) indicate rotation transformation counterclockwise
Wherein, θ indicates the angle between two synchronous rotating frames;
Step 3, it is as follows that high-frequency current response, process in estimation rotor coordinate are solved:
3.1, high-frequency voltage signal in estimation rotor coordinate is injected according to (5) formula, in conjunction with motor under high-frequency square-wave signal
Model (3) formula, obtains
In formula,To estimate shaftingAngle between actual rotor shafting dq, θeFor actual rotor position
It sets,To estimate rotor-position;LΣ=(Ld+Lq)/2 are mean value inductance, LΔ=(Ld-Lq)/2 are difference inductance;Then estimated
High-frequency current responds in coordinate system
3.2, bringing high frequency voltage in estimation frame shown in formula (5) into formula (8) must estimate that electric current is rung in rotor coordinate
It answers
The injector angle γ comprising variation in q axis high-frequency current signal, signal of the tradition based on the response of q shaft current are estimated in formula
Demodulating algorithm is no longer applicable in, and next design demodulates location information using high-frequency current response in injection coordinate system;
Step 4, the size of optimal injector angle γ is calculated, and provides foundation, process is as follows:
4.1, based under estimation d axis high-frequency voltage signal method for implanting, produced high-frequency current response vector causes tradition
Torque pulsation it is larger, internal permanent magnet synchronous motor torque capacity torque current ratio MTPA control in, there are torque isopleth
And the current phasor crosspoint under MTPA control, along this work point of intersection torque isopleth tangential direction current phasor to being
System influences minimum, and to obtain this optimum current signal, the high frequency square wave voltage signal that an angle is γ is injected, and this angle
γ should be separately measurable calculating, provide the calculated value of γ herein dependent on electric current operating point on MTPA curve:
It can be made location estimation angle by controller adjustingPhysical location θ in trackinge, then estimation frameWith actual coordinate
It is that dq is overlapped, then has
In formula, angle beta=θMTPAPi/2, θMTPAFor MTPA control under stator current vector angle, thus obtain one with
θMTPAThe injector angle γ of variation, i.e. operation torque loading condition variation, injector angle also change correspondingly;
Step 5, the estimated location information in high-frequency current response is demodulated, process is as follows:
5.1, shafting will be estimated in (9) formulaInterior high-frequency current response transform to injection shafting kl in,
Thus it obtains shown in the high-frequency current response signal such as formula (12) about rotor position error, in high-frequency voltage signal
It injects in coordinate system kl, position detection device makes Δ θeRotor estimated location is obtained for 0And since there are injector angles in above formula
γ, therefore position estimation error when stable state is γ, is unable to get rotor physical location,
Therefore it is accurate estimation rotor-position, is handled as follows:
It enables
Then have
5.2, above formula (15) is inputted as observer, after observer convergence, is then had
sin(2Δθe)=0 (16)
Obtaining estimated location is
Rotor estimated location is obtained according to formula (17) and converges on physical location, realizes permanent magnet synchronous motor position-sensor-free
Control.
Further, really in the step 5, due to the symmetry of rotor with salient pole, the identification of rotor polarity need to be carried out in advance, i.e.,
Determine d axis positive direction, accurately to obtain the initial position of rotor, guarantees the operation of motor normal starting.
The present invention use varied angle high frequency square wave voltage signal method for implanting, realized under optimal implant angle it is built-in forever
The smallest position Sensorless Control of magnetic-synchro motor torque ripple.
Technical concept of the invention are as follows: produced for conventional based in estimation d axis high-frequency voltage signal method for implanting
High-frequency current vector may cause the larger situation of torque pulsation, by change injection high frequency voltage vector angle, inside
Formula permanent magnet synchronous motor torque capacity electric current is set than under vector controlled, making its corresponding high-frequency current vector along torque isopleth
Tangential direction, to effectively reduce torque pulsation.Since angle of torsion is different under different loads working condition, high frequency is injected
Voltage vector signal angle is variation, by defining a new injection coordinate system, and injects high frequency square wave voltage signal, benefit
This optimum current vector is obtained with voltage-current relationship, to reduce the adverse effect to system, to reach additional Injection Signal
Cause the smallest purpose of torque pulsation.
The invention has the benefit that different loads working condition is directed under low speed, the torque according to MTPA vector controlled
Angle is different, calculates corresponding voltage injector angle, obtains best high-frequency current vector lesser to systematic influence, effectively reduces
Because extra injection causes the influence of torque pulsation, and it can guarantee the position and speed estimation essence of position Sensorless Control
Degree, improves system performance.
Detailed description of the invention
Fig. 1 is entire Control system architecture block diagram of the invention.
Fig. 2 is two-phase stationary coordinate system, practical two-phase synchronous rotating frame, estimation two-phase synchronous rotating frame and two
The mutually positional diagram between injection synchronous rotating frame.
Fig. 3 is optimal angle high-frequency voltage signal injecting principle schematic diagram.
Fig. 4 is PLL type rotor-position tracking observer figure.
Specific embodiment
The present invention will be further described with reference to the accompanying drawing.
- Fig. 4 referring to Fig.1, it is a kind of based on optimal injector angle high-frequency square-wave signal injection permanent magnet synchronous motor without position pass
Sensor control method, the control method the following steps are included:
Step 1, it is as follows that permanent magnet synchronous motor mathematical model, process under high frequency square wave voltage signal are established:
1.1, in dq two-phase synchronous rotating frame, the voltage status equation of internal permanent magnet synchronous motor IPMSM is used
The form of matrix is expressed as follows
In formula,Stator voltage and current phasor, R respectively under rotor reference systemsFor stator
Resistance, Ld、LqFor d, q axle inductance, ωeFor electrical angular speed, ψfFor PM rotor magnetic linkage amplitude;Subscript r indicates armature spindle
System;
1.2, the high-frequency voltage signal by frequency much larger than fundamental frequency injects IPMSM, and in the lower situation of revolving speed,
The voltage and back-emf voltage of stator resistance can be ignored, therefore, the high-frequency resistance model of IPMSM can be expressed simply as
Following pure inductance model:
In formula,High frequency voltage, current component respectively on d, q axis;Subscript h indicates high frequency content;
1.3, di/dt can be approximated to be Δ i/ Δ t in a switch periods, and formula (2) is rewritten as
In formula, Δ T indicates a switch periods, and (3) formula is motor discrete models under high-frequency square-wave signal;
Step 2, it calculates varied angle high frequency square wave and is infused in estimation rotor axial system component of voltage, process is as follows:
2.1, any synchronous rotating frame kl is defined, injects high frequency square wave voltage signal in its k axis
In formula,For the high frequency voltage for being injected separately into k axis and l axis in any synchronous rotating frame, VhFor note
Enter voltage magnitude, n indicates sampling sequence number;
2.2, the high-frequency voltage signal for injecting kl shafting is transformed into estimation synchronous rotating frameIt is interior, it obtains estimation and sits
Mark is interior high-frequency voltage signal
In formula,Respectively estimate in synchronous rotating frameAxis andHigh-frequency voltage signal, γ be injection
The synchronous rotary kl shafting of high-frequency signal and estimationAngle between shafting, i.e.,θkIndicate injection coordinate system and
Angle between rest frame, T (θ) indicate rotation transformation counterclockwise
Wherein, θ indicates the angle between two synchronous rotating frames;Relationship is as shown in Figure 2 between each coordinate system;
Step 3, it is as follows that high-frequency current response, process in estimation rotor coordinate are solved:
3.1, high-frequency voltage signal in estimation rotor coordinate is injected according to (5) formula, in conjunction with motor under high-frequency square-wave signal
Model (3) formula, obtains
In formula,To estimate shaftingAngle between actual rotor shafting dq, θeFor actual rotor position
It sets,To estimate rotor-position;LΣ=(Ld+Lq)/2 are mean value inductance, LΔ=(Ld-Lq)/2 are difference inductance;Then estimated
High-frequency current responds in coordinate system
3.2, bringing high frequency voltage in estimation frame shown in formula (5) into formula (8) must estimate that electric current is rung in rotor coordinate
It answers
The injector angle γ comprising variation in q axis high-frequency current signal, signal of the tradition based on the response of q shaft current are estimated in formula
Demodulating algorithm is no longer applicable in, and next design demodulates location information using high-frequency current response in injection coordinate system;
Step 4, the size of optimal injector angle γ is calculated, and provides foundation, process is as follows:
4.1, as shown in figure 3, tradition is based on estimation d axis high-frequency voltage signal uh1Under method for implanting, produced high-frequency current
Response vector ih1Caused torque pulsation is larger, in internal permanent magnet synchronous motor torque capacity torque current ratio MTPA control,
There are the current phasor crosspoints under torque isopleth and MTPA control, along the torque isopleth tangential direction of this work point of intersection
Current phasor ih2To systematic influence minimum, to obtain this optimum current signal, the high frequency square wave voltage that an angle is γ is believed
Number uh2It is injected, and this angle γ should be separately measurable calculating, provide γ's herein dependent on electric current operating point on MTPA curve
Calculated value:
It can be made location estimation angle by controller adjustingPhysical location θ in trackinge, then estimation frameWith actual coordinate
It is that dq is overlapped, then has
In formula, angle beta=θMTPAPi/2, θMTPAFor MTPA control under stator current vector angle, thus obtain one with
θMTPAThe injector angle γ of variation, i.e. operation torque loading condition variation, injector angle also change correspondingly;
Step 5, the estimated location information in high-frequency current response is demodulated, process is as follows:
5.1, shafting will be estimated in (9) formulaInterior high-frequency current response transform to injection shafting kl in,
Thus it obtains shown in the high-frequency current response signal such as formula (12) about rotor position error, in high-frequency voltage signal
It injects in coordinate system kl, position detection device makes Δ θeRotor estimated location is obtained for 0And since there are injector angles in above formula
γ, therefore position estimation error when stable state is γ, is unable to get rotor physical location,
Therefore it is accurate estimation rotor-position, is handled as follows:
It enables
Then have
5.2, rotor-position observer as shown in figure 4, by above formula (15) as observer input, when observer convergence after,
Then have
sin(2Δθe)=0 (33)
Obtaining estimated location is
Rotor estimated location is obtained according to formula (17) and converges on physical location, realizes permanent magnet synchronous motor position-sensor-free
Control.
Further, since the symmetry of rotor with salient pole, need to carry out the identification of rotor polarity in advance, that is, determine d axis positive direction, with
The accurate initial position for obtaining rotor guarantees the operation of motor normal starting.