CN105356806A - Permanent-magnet synchronous motor sensorless control method adopting square-wave injection - Google Patents

Abstract

A permanent-magnet synchronous motor sensorless control method adopting square-wave injection belongs to the field of motor control. The invention aims to solve the problem that the permanent-magnet synchronous motor is applicable to low-speed sensorless control technologies and the traditional sine signal injection method demands high injection frequency and is of poor dynamic performance. First, a square-wave voltage signal is injected to a control shafting; then, the signal is processed based on excited current response under an observation shafting which lags behind the control shafting by 45 degrees to obtain a position deviation signal; and finally, the observed value of the rotor position is obtained through a Luenberger observer. The method of the invention is applicable to permanent-magnet synchronous motor sensorless control.

Description

A kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection

Technical field

The invention belongs to Motor Control Field, relate to a kind of based on square-wave signal inject be applicable to low speed (zero-speed) permagnetic synchronous motor method for controlling position-less sensor.

Background technology

In recent years, Permanent-magnet Synchronous-motor Speed Servo System becomes the study hotspot in Prospect of AC Adjustable Speed Drive field gradually.Trace it to its cause, compared with traditional asynchronous machine, the advantage of permagnetic synchronous motor is: structure is simple, volume is little, lightweight, reliable, power density is high, good speed adjustment features etc., permagnetic synchronous motor has become the ideal chose of frequency control electric drive system, and its application is very extensive.According to the difference of permanent-magnetic synchronous motor rotor magnet structure, surface-mount type and built-in two kinds can be divided into.

At present, in the application of high-performance permanent magnet synchronous machine governing system, usual needs install the mechanical location detecting elements such as photoelectric encoder, resolver or Hall element to obtain rotor magnetic pole position information at motor shaft ends, but the installation of position transducer brings, and system cost increases, volume increases, reliability reduces problems, and limits the application scenario of permagnetic synchronous motor.Therefore, Low-cost, strong robustness position-sensor-free method for controlling permanent magnet synchronous motor, become the study hotspot in AC Motor Control technical field.

According to the scope of application of permagnetic synchronous motor position-sensor-free technology, usually two classes are divided into: a class is the position-sensor-free technology being applicable to high speed, another kind of is the position-sensor-free technology being applicable to low speed (zero-speed), realizes respectively according to motor fundamental frequency Mathematical Modeling and salient-pole structure characteristic.The back electromotive force that the permagnetic synchronous motor position-sensor-free technology being applicable to high speed is encouraged by fundamental frequency or flux linkage model observe rotor-position/velocity information, are referred to as modelling.The position-sensor-free technology being applicable to low speed (zero-speed) needs to inject high-frequency auxiliaring signal usually, carry out signal transacting by sampling high frequency response and then realize rotor-position observation, becoming the effective solution that current permagnetic synchronous motor position Sensorless Control low speed (zero-speed) is run.

But it is higher to Injection Signal frequency requirement that traditional sinusoidal signal injects form, especially under the condition that big-power transducer carrier frequency is lower because injected frequency and the less position error signal that causes of running frequency frequency difference extract difficulty.In addition, traditional high-frequency auxiliaring signal method for implanting being applicable to the operation of low speed (zero-speed) position-sensor-free, usually high frequency response signal is separated with fundamental frequency signal, position error signal extracts, and then limits the dynamic property of New method for sensorless control technique of PMSM to need to adopt filter to realize.Therefore, for New method for sensorless control technique of PMSM, inject form for square-wave signal, simplify signal processing, cancel filter effect, most important to its dynamic response capability of raising.

Summary of the invention

The present invention seeks to solve the existing permagnetic synchronous motor Sensorless Control Technique being applicable to low speed (zero-speed), need to adopt filter at signal processing, the problems such as dynamic performance is poor, provide a kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection.

Adopt a permagnetic synchronous motor method for controlling position-less sensor for Square wave injection, it is characterized in that, the method comprises the following steps:

Step one, based on permagnetic synchronous motor high frequency Mathematical Modeling, inject square wave voltage signal at Control Shaft system d axle, and high-frequency current response signal and fundamental frequency signal under extracting Control Shaft system;

High-frequency current response signal and fundamental frequency signal under extraction Control Shaft system described in step one, this leaching process is without the need to using filter, and leaching process is:

Step is one by one, by Park conversion by the three-phase current i obtained that samples _a, i _b, i _cunder transforming to Control Shaft system, obtain current signal i under Control Shaft system _d, i _q, wherein, for position detection value; Its process is:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\widehat{\mathrm{\θ}}}_e& \cos ({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3})& \cos ({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3})\\ -\sin {\widehat{\mathrm{\θ}}}_e& -\sin ({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3})& -\sin ({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]$

Step one two, obtain high-frequency current response signal i under Control Shaft system by doing difference process _dh(k), i _qh(k), wherein, k is sampling instant; Its process is:

$\left\{\begin{array}{c}{i}_{dh}\left(k\right)=\frac{i_d\left(k\right)-i_d(k-1)}{2}\\ i_{qh}\left(k\right)=\frac{i_q\left(k\right)-i_q(k-1)}{2}\end{array}\right.;$

Step one three, obtain fundamental frequency signal i under Control Shaft system by summation process _d1(k), i _q1(k), its process is:

$\left\{\begin{array}{c}{i}_{d1}\left(k\right)=\frac{i_d\left(k\right)+i_d(k-1)}{2}\\ i_{q1}\left(k\right)=\frac{i_q\left(k\right)+i_q(k-1)}{2}\end{array}\right..$

High-frequency current response signal under Control Shaft system is transformed to Observing axis system by step 2, employing coordinate transform, obtains position error signal by signal transacting;

High-frequency current response signal under Control Shaft system is transformed to Observing axis system by the employing coordinate transform described in step 2, obtains position error signal by signal transacting, and this leaching process is without the need to introducing low pass filter, and leaching process is as follows:

Step 2 one, by Park conversion by high-frequency current response signal i under Control Shaft system _dh(k), i _qhk (), obtains under transforming to the Observing axis system of Delay control axle system 45 ° of electrical degrees its detailed process is:

$\left[\begin{array}{c}{i}_{dh}^m\\ i_{qh}^m\end{array}\right]=\left[\begin{array}{cc}cos\frac{\mathrm{\π}}{4}& -sin\frac{\mathrm{\π}}{4}\\ sin\frac{\mathrm{\π}}{4}& \cos \frac{\mathrm{\π}}{4}\end{array}\right]\left[\begin{array}{c}{i}_{dh}\\ i_{qh}\end{array}\right];$

Step 2 two, obtain position error signal ε by difference processing _e, its detailed process is:

$\begin{array}{c}{\mathrm{\ϵ}}_e=\[i_{qh}^m\left(k\right)-i_{dh}^m\left(k\right)\]-\[i_{qh}^m(k-1)-i_{dh}^m(k-1)\]\\ =\[i_{qh}^m\left(k\right)-i_{qh}^m(k-1)\]-\[i_{dh}^m\left(k\right)-i_{dh}^m(k-1)\]\end{array}.$

Step 3, the Luenberger observer passed through based on mechanical model obtain rotor-position measured value.

The Luenberger observer passed through based on mechanical model described in step 3 obtains rotor-position measured value, and wherein, the Luenberger observer based on mechanical model realizes without delayed phase, and rotational speed extraction is without the need to low pass filter.

Beneficial effect: permagnetic synchronous motor low speed (zero-speed) Sensorless Control Technique injected based on square-wave signal that the present invention adopts, signal processing method is simple, reliable and practical, without the need to adopting filter, improve New method for sensorless control technique of PMSM dynamic property; Can be widely applied in control system for permanent-magnet synchronous motor, not need extra hardware expense, good control performance can be obtained.

The invention provides a kind of rotor position observation method injected based on square-wave signal, its signal processing, without the need to adopting filter, effectively can improve permagnetic synchronous motor position-sensorless control system low speed (zero-speed) dynamic response capability.The present invention is applicable to permagnetic synchronous motor position Sensorless Control.

Accompanying drawing explanation

Fig. 1 is a kind of theory diagram adopting the permagnetic synchronous motor method for controlling position-less sensor of Square wave injection;

Fig. 2 is injecting voltage and response current schematic diagram;

Fig. 3 is that Control Shaft system high-frequency current response signal is separated block diagram with fundamental frequency signal;

Fig. 4 is position error signal leaching process block diagram;

Fig. 5 is the Luenberger rotor-position observer theory diagram based on mechanical model;

Fig. 6 is the coordinate system relation schematic diagram that a kind of permagnetic synchronous motor method for controlling position-less sensor adopting square-wave signal to inject relates to.

Embodiment

Embodiment one, illustrate present embodiment referring to figs. 1 through Fig. 6, a kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection described in present embodiment, the method comprises the following steps:

Step one, based on permagnetic synchronous motor high frequency Mathematical Modeling, inject square wave voltage signal at Control Shaft system d axle, and high-frequency current response signal and fundamental frequency signal under extracting Control Shaft system, concrete grammar is as follows:

Step one by one, based on permagnetic synchronous motor high frequency Mathematical Modeling, be f in Control Shaft system d axle injected frequency _s=1/T _s, amplitude is square wave voltage signal

Carry out Park conversion according to formula (1) and current signal i under Control Shaft system can be obtained _d, i _q, wherein, for position detection value;

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\widehat{\mathrm{\θ}}}_e& \cos ({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3})& \cos ({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3})\\ -\sin {\widehat{\mathrm{\θ}}}_e& -\sin ({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3})& -\sin ({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3})\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right]---\left(1\right)$

Step one two, obtain high-frequency current response signal i under Control Shaft system according to formula (2) by doing difference process _dh(k) and i _qh(k), wherein, k is sampling instant;

$\left\{\begin{array}{c}{i}_{dh}\left(k\right)=\frac{i_d\left(k\right)-i_d(k-1)}{2}\\ i_{qh}\left(k\right)=\frac{i_q\left(k\right)-i_q(k-1)}{2}\end{array}\right.---\left(2\right)$

Step one three, obtain fundamental frequency signal i under Control Shaft system according to formula (3) by summation process _d1(k) and i _q1(k),

$\left\{\begin{array}{c}{i}_{d1}\left(k\right)=\frac{i_d\left(k\right)+i_d(k-1)}{2}\\ i_{q1}\left(k\right)=\frac{i_q\left(k\right)+i_q(k-1)}{2}\end{array}\right.---\left(3\right)$

High-frequency current response signal under Control Shaft system is transformed to Observing axis system by step 2, employing coordinate transform, and obtain position error signal by signal transacting, concrete grammar is as follows:

Step 2 one, according to formula (4), by Park conversion by high-frequency current response signal i under Control Shaft system _dh(k), i _qhk (), obtains under transforming to the Observing axis system of Delay control axle system 45 ° of electrical degrees

$\left[\begin{array}{c}{i}_{dh}^m\\ i_{qh}^m\end{array}\right]=\left[\begin{array}{cc}cos\frac{\mathrm{\π}}{4}& -sin\frac{\mathrm{\π}}{4}\\ sin\frac{\mathrm{\π}}{4}& \cos \frac{\mathrm{\π}}{4}\end{array}\right]\left[\begin{array}{c}{i}_{dh}\\ i_{qh}\end{array}\right]---\left(4\right)$

Step 2 two, according to formula (5), obtain position error signal ε by difference processing _e,

$\begin{array}{c}{\mathrm{\ϵ}}_e=\[i_{qh}^m\left(k\right)-i_{dh}^m\left(k\right)\]-\[i_{qh}^m(k-1)-i_{dh}^m(k-1)\]\\ =\[i_{qh}^m\left(k\right)-i_{qh}^m(k-1)\]-\[i_{dh}^m\left(k\right)-i_{dh}^m(k-1)\]\end{array}---\left(5\right)$

Step 3, the Luenberger observer passed through based on mechanical model obtain rotor-position measured value.

Indicate item: all angles mentioned in the present invention are electrical degree.

Permanent magnet synchronous motor is the key link of ac synchronous motor governing system, shown in Figure 6, and getting rotor permanent magnet first-harmonic excitation field axis is d axle, and q axle is along 90 degree, the advanced d axle of direction of rotation, and d-q axle system companion rotor is with angular velocity omega _rrotate together, its space coordinates is with the angle of d axle with reference axis a phase between centers represent, regulation a phase place axle---reference axis a phase axle is zero degree.Then initial position angle of rotor for rotor field time initial and the angle between reference axis a phase axle.Delay control axle system of Observing axis system 45 ° of electrical degrees, i.e. d ^m45 °, the delayed d axle of axle, q ^m45 °, the delayed q axle of axle.

The present invention adopts square-wave signal to inject and realizes permagnetic synchronous motor low speed (zero-speed) position Sensorless Control, and purport is that the signal processing mode by simplifying cancels filter to the impact of control system dynamic property, improves dynamic response capability.Be described in detail according to Fig. 1-Fig. 5 below:

Suppose to inject high-frequency voltage signal frequency enough high, and much larger than fundamental frequency, so the back electromotive force of permanent magnet, rotational voltage and Stator resistance voltage dropping are negligible, therefore can obtain permagnetic synchronous motor high frequency Mathematical Modeling under Control Shaft system:

$\left[\begin{array}{c}{u}_{dh}\\ u_{qh}\end{array}\right]=L_{dq}^{c}p\left[\begin{array}{c}{i}_{dh}\\ i_{qh}\end{array}\right]---\left(6\right)$

In formula, $L_{dq}^c=\mathrm{\Σ}L\left[\begin{array}{cc}1& 0\\ 0& 1\end{array}\right]+\mathrm{\Δ}L\left[\begin{array}{cc}\cos \left(2{\mathrm{\θ}}_{rr}\right)& -\sin \left(2{\mathrm{\θ}}_{rr}\right)\\ -\sin \left(2{\mathrm{\θ}}_{rr}\right)& -\cos \left(2{\mathrm{\θ}}_{rr}\right)\end{array}\right]$ For permagnetic synchronous motor inductance matrix under Control Shaft system, for average inductance, for differential inductance, for position deviation angle, L _d, L _qfor dq axle inductance, θ _e, for position actual value, measured value.

Formula (6) is transformed to Observing axis system, can obtain

$p\left[\begin{array}{c}{i}_{dh}^m\\ i_{qh}^m\end{array}\right]=\frac{U_d^{inj}}{\sqrt{2}({\mathrm{\ΣL}}^2-{\mathrm{\ΔL}}^2)}\left[\begin{array}{c}\mathrm{\Σ}L-\mathrm{\Δ}L\left(\cos \right(2{\mathrm{\θ}}_{rr})+\sin \left(2{\mathrm{\θ}}_{rr}\right))\\ \mathrm{\Σ}L-\mathrm{\Δ}L\left(\cos \right(2{\mathrm{\θ}}_{rr})-\sin \left(2{\mathrm{\θ}}_{rr}\right))\end{array}\right]---\left(7\right)$

And then position error signal can be obtained be

$p(i_{qh}^m-i_{dh}^m)=\frac{U_d^{inj}}{\sqrt{2}({\mathrm{\ΣL}}^2-{\mathrm{\ΔL}}^2)}\·2\mathrm{\Δ}Lsin\left(2{\mathrm{\θ}}_{err}\right)---\left(8\right)$

And then by first-order difference be similar to, can as Suo Shi formula (5) position error signal form.

With reference to Fig. 1, its control procedure is described:

Gather the three-phase current i of motor PMSM _a, i _b, i _c, and obtain current signal i under Control Shaft system by Park conversion _d, i _q, current signal i under Control Shaft system _d, i _qhigh-frequency current response signal i under Control Shaft system is obtained respectively after fundamental frequency is separated with high-frequency signal _dh, i _qhwith fundamental frequency signal i under Control Shaft system _d1, i _q1;

High-frequency current response signal i under Control Shaft system _dh, i _qhposition error signal ε is obtained after deviation signal is extracted _e, position error signal ε _eposition detection value is obtained after Luenberger observer with rotor feedback angular speed

Angular speed with rotor feedback angular speed do difference, PI computing is carried out to this difference and obtains given value of current value given value of current value with fundamental frequency signal i under Control Shaft system _q1do difference, after PI computing is carried out to this difference, obtain q shaft voltage set-point

Given value of current value with fundamental frequency signal i under Control Shaft system _d1do difference, after PI computing is carried out to this difference, obtain d shaft voltage set-point

Now, be f in Control Shaft system d axle injected frequency _s=1/T _s, amplitude is square wave voltage signal d shaft voltage set-point with square wave voltage signal do and obtain d axle input signal

D axle input signal q shaft voltage set-point with position detection value the given voltage of α axle is obtained after Park inverse transformation voltage given with β axle

According to the given voltage of described α axle voltage given with β axle obtain modulation ratio, carry out SVPWM computing, and then the pulse width signal S of generating power device _abc; Pulse width signal S _abccontrol inverter unit, thus control motor rotation.

Claims (4)

1. adopt a permagnetic synchronous motor method for controlling position-less sensor for Square wave injection, it is characterized in that, the method comprises the following steps:

Step one, based on permagnetic synchronous motor high frequency Mathematical Modeling, inject square wave voltage signal at Control Shaft system d axle, and high-frequency current response signal and fundamental frequency signal under extracting Control Shaft system;

High-frequency current response signal under Control Shaft system is transformed to Observing axis system by step 2, employing coordinate transform, obtains position error signal by signal transacting;

Step 3, the Luenberger observer passed through based on mechanical model obtain rotor-position measured value.

2. a kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection according to claim 1, it is characterized in that, high-frequency current response signal and fundamental frequency signal under extraction Control Shaft system described in step one, this leaching process is without the need to using filter, and leaching process is:

Step is one by one, by Park conversion by the three-phase current i obtained that samples _a, i _b, i _cunder transforming to Control Shaft system, obtain current signal i under Control Shaft system _d, i _q, its process is:

$\left[\begin{array}{c}{i}_d\\ i_q\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}\cos {\widehat{\mathrm{\θ}}}_e& \cos \left({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3}\right)& \cos \left({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3}\right)\\ -\sin {\widehat{\mathrm{\θ}}}_e& -\sin \left({\widehat{\mathrm{\θ}}}_e-\frac{2\mathrm{\π}}{3}\right)& -\sin \left({\widehat{\mathrm{\θ}}}_e+\frac{2\mathrm{\π}}{3}\right)\end{array}\right]\left[\begin{array}{c}{i}_a\\ i_b\\ i_c\end{array}\right];$

Wherein, for position detection value;

Step one two, obtain high-frequency current response signal i under Control Shaft system by doing difference process _dh(k), i _qh(k), its process is:

$\left\{\begin{array}{c}{i}_{dh}\left(k\right)=\frac{i_d\left(k\right)-i_d(k-1)}{2}\\ i_{qh}\left(k\right)=\frac{i_q\left(k\right)-i_q(k-1)}{2}\end{array}\right.;$ Wherein, k is sampling instant;

Step one three, obtain fundamental frequency signal i under Control Shaft system by summation process _d1(k), i _q1(k), its process is:

$\left\{\begin{array}{c}{i}_{d1}\left(k\right)=\frac{i_d\left(k\right)+i_d(k-1)}{2}\\ i_{q1}\left(k\right)=\frac{i_q\left(k\right)+i_q(k-1)}{2}\end{array}\right..$

3. a kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection according to claim 1, it is characterized in that high-frequency current response signal under Control Shaft system is transformed to Observing axis system by the employing coordinate transform described in step 2, position error signal is obtained by signal transacting, this leaching process is without the need to introducing low pass filter, and leaching process is as follows:

Step 2 one, by Park conversion by high-frequency current response signal i under Control Shaft system _dh(k), i _qhk (), obtains under transforming to the Observing axis system of Delay control axle system 45 ° of electrical degrees its detailed process is:

$\left[\begin{array}{c}{i}_{dh}^m\\ i_{qh}^m\end{array}\right]=\left[\begin{array}{cc}cos\frac{\mathrm{\π}}{4}& -sin\frac{\mathrm{\π}}{4}\\ sin\frac{\mathrm{\π}}{4}& \cos \frac{\mathrm{\π}}{4}\end{array}\right]\left[\begin{array}{c}{i}_{dh}\\ i_{qh}\end{array}\right];$

Step 2 two, obtain position error signal ε by difference processing _e, its detailed process is:

$\begin{array}{c}{\mathrm{\ϵ}}_e=\[i_{qh}^m\left(k\right)-i_{dh}^m\left(k\right)\]-\[i_{qh}^m\left(k-1\right)-i_{dh}^m\left(k-1\right)\]\\ =\[i_{qh}^m\left(k\right)-i_{qh}^m\left(k-1\right)\]-\[i_{dh}^m\left(k\right)-i_{dh}^m\left(k-1\right)\]\end{array}.$

4. a kind of permagnetic synchronous motor method for controlling position-less sensor adopting Square wave injection according to claim 1, it is characterized in that the Luenberger observer passed through based on mechanical model described in step 3 obtains rotor-position measured value, wherein, Luenberger observer based on mechanical model realizes without delayed phase, and rotational speed extraction is without the need to low pass filter.