CN101043194A - Vector control method and apparatus for induction motor - Google Patents

Abstract

A type of vector control method and device of induction-motor, thereinto the magnetic chain observation steps includes: firstly calculating the voltage module and current module to obtain the magnetic chain psi rhpf and psi rlpf, then two part of magnetic chain are added and transformed from orthogonal coordinate to polar coordinate to obtain the magnetic chain angle theta s and the magnetic chain amplitude, the magnetic chain angle theta s is parameter to feedback to step of calculating current module. The invention combines the advantages of voltage module method, current module method, offsets its defects, and adopts the improved voltage module method. Considering the characters of voltage module and current module, combining two together, the voltage module operates in high speed, and the observation value of current module is filtered by lowpass; the current module operates in low speed, and the observation value of voltage module is filtered by highpass, so magnetic chain possesses higher precision in high speed and low speed.

Description

A kind of vector control method of induction motor and device

Technical field

The present invention relates to electric motors, especially for the Speedless sensor vector control method of the changed speed operation of control of induction.

Background technology

Along with the introducing of vector control theory and the development of high performance central processing unit (CPU) and digital signal processor (DSP), can do changed speed operation by the high performance of control induction motor.Promptly need the velocity information or the magnetic flux information of induction motor to come induction motor is carried out vector control.Usually for detection speed information or magnetic flux information, need velocity transducer or magnetic flux transducer, such as speed machine, resolver or pulse coder.But the electronic circuit of transducer is limited to aspect serviceability temperature, signal connection charge height between velocity transducer and the current transformer, and the coupling part between induction motor and the velocity transducer will experience a shock, and considers preferably to avoid using transducer for equipment dependability.Therefore proposed the various induction motor velocity estimation methods of vector control equipment without sensor recently, but existing method all there is limitation separately.

Existing method one is based on the model reference adaptive system, the main thought of MRAS (Model Reference Adaptive System) method identified parameters is to remain the equation of estimated parameter as adjustable model with containing, with the equation that do not contain unknown parameter as the reference model, the parameter of utilizing the deviation of two model output variables to come the real-time regulated adjustable model according to certain adaptive rate.The block diagram of MRAS method as shown in Figure 1, there is following problem in it: at first, there is the problem of a convergence rate in the MRAS method.Because rotating speed of motor does not directly calculate, but by self-adaptive regulator by regulating and control produces, the convergence rate of self-adaptive regulator and the parameter correlation of adjuster.Secondly, there is the problem of stability in the MRAS method.There is a stable parameter area in self-adaptive regulator, and for different motors, the parameter area of regulator stable is different.The designer also must the convergence rate of self-adaptive regulator and stable aspect do that some are compromise.In addition, the structure of MRAS method is comparatively complicated, implements also comparatively difficulty.

Existing method two is improved voltage model method, and the voltage model method of motor magnetic linkage is improved, and its principle as shown in Figure 2.Substitute the pure integrator of employing with one order inertia filtering link and carry out back electromotive force calculating, when low cruise, the calculated value and the actual value of one order inertia filtering link differ greatly, and disturb mutually with spinner velocity, make and to carry out vector control completely, concerning carry out suitable vector control in whole velocity interval, this solution is not satisfied.Secondly, the compensation rate of flux observation is the rotor flux set-point, flux observer in the process that the magnetic linkage amplitude changes, as: start-up course, exciting current exchange to inject realizes that Speedless sensor Rr identification, weak magnetic control system etc. all can not accurately observe.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of vector control method of induction motor, can carry out the observation of stable and accurate control motor magnetic linkage and rotating speed.

In order to solve the problems of the technologies described above, the present invention adopts following technical scheme: a kind of vector control method of induction motor, the step that comprises flux observation, it is characterized in that described flux observation step comprises following a few step: carry out voltage model calculating and current model at first respectively and calculate magnetic linkage ψ _RhpfAnd ψ _Rlpf, the addition of two parts magnetic linkage is carried out rectangular coordinate/polar coordinate transform again and is obtained magnetic linkage angle θ then _sWith the magnetic linkage amplitude, magnetic linkage angle θ _sFeed back to again in the current model calculation procedure as parameter and to go.

Described current model calculates and may further comprise the steps:

1) rotation transformation is according to the current i s and angle, the magnetic field θ of motor detection _sObtain the motor stator current i s under the alpha-beta coordinate system _α, is _β,

Is={is _α, is _β} ^T, calculate the motor-field current i s under the synchronous rotation d-q coordinate system then _d,

$\left[\begin{array}{c}{\mathrm{is}}_d\\ {\mathrm{is}}_q\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\θ}}_s& \sin {\mathrm{\θ}}_s\\ -\sin {\mathrm{\θ}}_s& {\cos \mathrm{\θ}}_s\end{array}\right]\left[\begin{array}{c}{\mathrm{is}}_{\mathrm{\α}}\\ {\mathrm{is}}_{\mathrm{\β}}\end{array}\right]$

Is _qBe the motor torque electric current;

2) electric current magnetic linkage Model Calculation is used above-mentioned motor-field current i s _dCalculate magnetic linkage ψ under the synchronous rotation d-q coordinate system _Rd,

${\mathrm{\&psi;}}_{\mathrm{rd}}=\frac{{\mathrm{<figure-callout\; id="1"\; label="L\; m"\; filenames="A20061002502500151.png"\; state="\{\{state\}\}">L</figure-callout>}}_m}{1+{\mathrm{\&tau;}}_{r}s}{i}_{\mathrm{sd}}$

In the formula, τ _rBe rotor time constant, L _mBe the electric machine rotor mutual inductance;

3) magnetic linkage ψ under the above-mentioned d-q coordinate system is used in rotation inverse transformation _RdCarry out inverse transformation, calculate the magnetic linkage ψ r under the alpha-beta coordinate system

4) low-pass filtering, by the second integral device, the measured value of when high speed current model being calculated filters,

Promptly obtain magnetic linkage ψ _Rlpf

Described voltage model calculates and comprises following two steps:

1) back electromotive force calculates, and the voltage U s that current i s that detects according to motor and inverter send calculates counter electromotive force of motor e,

$\stackrel{\&OverBar;}{e}=\frac{L_r}{L_m}(\stackrel{\&OverBar;}{\mathrm{Us}}-\mathrm{Rs}\&CenterDot;\mathrm{is}-\mathrm{\&sigma;Ls}\frac{d}{\mathrm{dt}}\mathrm{is})$

In the formula, e is a counter electromotive force of motor, L _rBe rotor inductance, L _mBe the electric machine rotor mutual inductance, Rs is a motor stator resistance, L _sBe the rotor inductance, σ is a motor leakage inductance coefficient;

2) high-pass filtering, by first integrator, the measured value of when low speed voltage model being calculated filters, and promptly obtains magnetic linkage ψ _Rhpf,

Described magnetic linkage addition and rectangular coordinate/polar coordinate transform process is the magnetic linkage ψ that voltage model calculates _RhpfMagnetic linkage ψ with electric current calculating _RlpfThe motor magnetic linkage that the process addition obtains observing

$\widehat{{\mathrm{\&psi;}}_r}={\mathrm{\&psi;}}_{\mathrm{rlpf}}+{\mathrm{\&psi;}}_{\mathrm{hpfr}},$ Therefore, the magnetic linkage computing formula of mixing is:

The magnetic linkage that calculates obtains magnetic linkage amplitude and magnetic linkage angle through rectangular coordinate/polar coordinate transform again,

${\mathrm{\&theta;}}_s=\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}.$

The magnetic linkage angle θ that calculates _sFeed back to rotation transformation and rotation inverse transformation as parameter.

The present invention provides a kind of vector control apparatus of induction motor simultaneously, comprises the flux observation module, and described flux observation module comprises voltage model part, current model part, adder, rectangular coordinate/polar coordinate transform device and a feedback device.

Described current model partly comprises:

1) rotation transformation device is according to the current i s and angle, the magnetic field θ of motor detection _sObtain the motor stator current i s under the alpha-beta coordinate system _α, is _β,

Is={is _α, is _βT, calculate the motor-field current i s under the synchronous rotation d-q coordinate system then _d,

$\left[\begin{array}{c}{\mathrm{is}}_d\\ {\mathrm{is}}_q\end{array}\right]=\left[\begin{array}{cc}{\cos \mathrm{\&theta;}}_s& {\sin \mathrm{\&theta;}}_s\\ -\sin {\mathrm{\&theta;}}_s& {\cos \mathrm{\&theta;}}_s\end{array}\right]\left[\begin{array}{c}{\mathrm{is}}_{\mathrm{\&alpha;}}\\ {\mathrm{is}}_{\mathrm{\&beta;}}\end{array}\right]$

Is _qBe the motor torque electric current;

2) electric current magnetic linkage Model Calculation device uses above-mentioned motor-field current i s _dCalculate magnetic linkage ψ under the synchronous rotation d-q coordinate system _Rd,

${\mathrm{\&psi;}}_{\mathrm{rd}}=\frac{{\mathrm{<figure-callout\; id="1"\; label="L\; m"\; filenames="A20061002502500151.png"\; state="\{\{state\}\}">L</figure-callout>}}_m}{1+{\mathrm{\&tau;}}_{r}s}{i}_{\mathrm{sd}}$

In the formula, τ _rBe rotor time constant, L _mBe the electric machine rotor mutual inductance;

3) the rotation inverter uses magnetic linkage ψ under the above-mentioned d-q coordinate system _RdCarry out inverse transformation, calculate the magnetic linkage ψ under the alpha-beta coordinate system _r

4) low-pass filter, by the second integral device, the measured value with current model when high speed filters,

Promptly obtain magnetic linkage ψ _Rlpf

Described voltage model partly comprises:

1) back electromotive force calculation element, the voltage U s that current i s that detects according to motor and inverter send calculates counter electromotive force of motor e,

$\stackrel{\&OverBar;}{e}=\frac{L_r}{L_m}(\stackrel{\&OverBar;}{\mathrm{Us}}-\mathrm{Rs}\&CenterDot;\mathrm{is}-\mathrm{\&sigma;Ls}\frac{d}{\mathrm{dt}}\mathrm{is})$

In the formula, e is a counter electromotive force of motor, L _rBe rotor inductance, L _mBe the electric machine rotor mutual inductance, Rs is a motor stator resistance, L _sBe the rotor inductance, σ is a motor leakage inductance coefficient;

2) high pass filtering device by first integrator, obtains magnetic linkage ψ _Rhpf,

Described adder and rectangular coordinate/polar coordinate transform device, the magnetic linkage ψ of voltage model method _rWith current model method magnetic linkage ψ _RlpfThe motor magnetic linkage that the process adder obtains observing

${\widehat{\mathrm{\&psi;}}}_r={\mathrm{\&psi;}}_{\mathrm{rlpf}}+{\mathrm{\&psi;}}_{\mathrm{hpfr}}$

Therefore, the magnetic linkage computing formula of mixed model is:

The magnetic linkage that calculates obtains magnetic linkage amplitude and magnetic linkage angle through rectangular coordinate/polar coordinate transform again,

${\mathrm{\&theta;}}_s=\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}.$

Feedback device is with the magnetic linkage angle θ that calculates _sFeed back to rotation transformation device and rotation inverter as parameter.

The present invention on the basis that compensates its defect, has adopted the improvement voltage model method in the advantage in conjunction with voltage model method, current model method.Consider the characteristics separately of voltage model and current model, both are combined use, promptly when high speed, allow voltage model work, filter by the measured value of low pass filter with current model; Allow current model work when low speed, by high pass filter the voltage model measured value is filtered, flux observation all has higher accuracy when high speed and low speed like this.

Algorithm of the present invention is stable, and estimated value has robustness preferably to the fast convergence rate of actual value to variation of controlled object parameter and measurement noise, and only in complexity, it is comparatively convenient to implement on the structure.

Description of drawings

Fig. 1 is a kind of prior art, the block diagram of MRAS method identifying motor rotating speed.

Fig. 2 is another kind of prior art, improves the theory diagram of voltage model method.

Fig. 3 is the block diagram of flux observation module of the present invention.

Fig. 4 is one embodiment of the present of invention, a kind of Speedless sensor vector control The general frame.

Embodiment

Fig. 4 is the embodiment of a speed-less sensor vector control system of the present invention, and existing just Fig. 4 describes.The current of electric that detects is through 3/2 conversion, is after the conversion _α, is _βBe the motor stator electric current under the alpha-beta coordinate system.Simultaneously, the voltage U s that sends of inverter _α, Us _βEnter flux observation module of the present invention, is _α, is _βEnter the rotating coordinate transformation module simultaneously, obtain is _d, is _qFor rotating the motor stator electric current under the d-q coordinate system synchronously.Field supply is _dEnter the flux observation module.By the calculating of flux observation module, the motor synchronous rotating speed that obtains estimating

Given magnetic linkage ψ _r ^*With given motor torque current i s _q ^*Enter the slippage computing module, obtain the slippage rotational speed omega _Sl ^*, the motor synchronous rotational speed omega _sWith the slippage rotational speed omega _Sl ^*Calculate rotor speed through subtracter, pass through low pass filter filtering again, the rotor speed that obtains estimating.Rotor speed of estimating and given rotating speed pass through speed control again through subtracter, speed control output order motor torque, and the instruction motor torque calculates given motor torque electric current through the torque current computing module; Instruction magnetic linkage ψ _r ^*Through the magnetic field calculation module, calculate given motor-field electric current.The given motor torque electric current and the motor torque electric current of detection enter subtracter, pass through current controller again, produce given motor torque voltage; The given motor-field electric current and the motor-field electric current of detection enter subtracter, pass through current controller again, produce given motor-field voltage.Given motor torque voltage and given motor-field voltage add bucking voltage respectively, enter rotation transform module, by the voltage transformation module, are applied on the three-phase induction motor then.

Wherein, the calculating of flux observation module comprises voltage model part, current model part, adder, rectangular coordinate/polar coordinate transform device and a feedback device.

Described current model partly comprises:

1) rotation transformation device is according to the current i s and angle, the magnetic field θ of motor detection _sObtain the motor stator current i s under the alpha-beta coordinate system _α, is _β,

Is={is _α, is _βT, calculate the motor-field current i s under the synchronous rotation d-q coordinate system then _d,

$\left[\begin{array}{c}{\mathrm{is}}_d\\ {\mathrm{is}}_q\end{array}\right]=\left[\begin{array}{cc}{\cos \mathrm{\&theta;}}_s& {\sin \mathrm{\&theta;}}_s\\ -{\sin \mathrm{\&theta;}}_s& {\cos \mathrm{\&theta;}}_s\end{array}\right]\left[\begin{array}{c}{\mathrm{is}}_{\mathrm{\&alpha;}}\\ {\mathrm{is}}_{\mathrm{\&beta;}}\end{array}\right]$

Is _qBe the motor torque electric current;

2) electric current magnetic linkage Model Calculation device uses above-mentioned motor-field current i s _dCalculate magnetic linkage ψ under the synchronous rotation d-q coordinate system _Rd,

${\mathrm{\&psi;}}_{\mathrm{rd}}=\frac{{\mathrm{<figure-callout\; id="1"\; label="L\; m"\; filenames="A20061002502500151.png"\; state="\{\{state\}\}">L</figure-callout>}}_m}{1+{\mathrm{\&tau;}}_{r}s}{i}_{\mathrm{sd}}$

In the formula, τ _rBe rotor time constant, L _mBe the electric machine rotor mutual inductance;

3) the rotation inverter uses magnetic linkage ψ under the above-mentioned d-q coordinate system _RdCarry out inverse transformation, calculate the magnetic linkage ψ under the alpha-beta coordinate system _r

4) low-pass filter, by the second integral device, the measured value with current model when high speed filters,

Promptly obtain magnetic linkage ψ _Rlpf

Described voltage model partly comprises:

1) back electromotive force calculation element, the voltage U s that current i s that detects according to motor and inverter send calculates counter electromotive force of motor e,

$\stackrel{\&OverBar;}{e}=\frac{L_r}{L_m}(\stackrel{\&OverBar;}{\mathrm{Us}}-\mathrm{Rs}\&CenterDot;\mathrm{is}-\mathrm{\&sigma;Ls}\frac{d}{\mathrm{dt}}\mathrm{is})$

In the formula, e is a counter electromotive force of motor, L _rBe rotor inductance, L _mBe the electric machine rotor mutual inductance, Rs is a motor stator resistance, L _sBe the rotor inductance, σ is a motor leakage inductance coefficient;

2) high pass filtering device by first integrator, obtains magnetic linkage ψ _Rhpf,

Described adder and rectangular coordinate/polar coordinate transform device, the magnetic linkage ψ of voltage model method _rWith current model method magnetic linkage ψ _RlpfThe motor magnetic linkage that the process adder obtains observing

${\widehat{\mathrm{\&psi;}}}_r={\mathrm{\&psi;}}_{\mathrm{rlpf}}+{\mathrm{\&psi;}}_{\mathrm{hpfr}}$

Therefore, the magnetic linkage computing formula of mixed model is:

The magnetic linkage that calculates obtains magnetic linkage amplitude and magnetic linkage angle through rectangular coordinate/polar coordinate transform again,

${\mathrm{\&theta;}}_s=\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}.$

Feedback device is with the magnetic linkage angle θ that calculates _sFeed back to rotation transformation device and rotation inverter as parameter.

The rotating speed of speed-less sensor vector control system is estimated according to the magnetic linkage that observes.

By vector correlation as can be known, synchronous rotary speed:

${\mathrm{\&omega;}}_s=\frac{d}{\mathrm{dt}}{\mathrm{\&theta;}}_s=\frac{d}{\mathrm{dt}}\left[\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}\right]=\frac{p{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}-p{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}^2+{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}^2}$

The computing formula of slip-frequency has different expression-forms under different reference frames.In rotor field-oriented control:

${\mathrm{\&omega;}}_{\mathrm{sl}}=\frac{L_m}{{\mathrm{\&tau;}}_r}\frac{i_{\mathrm{sq}}}{{\mathrm{\&psi;}}_{\mathrm{rd}}}$

ω _SlBe slip-frequency, then the rotor speed of Gu Jiing is:

ω _r＝ω _s-ω _sl

The present invention on the basis that compensates its defect, has adopted the improvement voltage model method in the advantage in conjunction with voltage model method, current model method.Consider the characteristics separately of voltage model and current model, both are combined use, promptly when high speed, allow voltage model work, filter by the measured value of low pass filter with current model; Allow current model work when low speed, by high pass filter the voltage model measured value is filtered, flux observation all has higher accuracy when high speed and low speed like this.

Algorithm of the present invention is stable, and estimated value has robustness preferably to the fast convergence rate of actual value to variation of controlled object parameter and measurement noise, and only in complexity, it is comparatively convenient to implement on the structure.

Claims (8)

1. the vector control method of an induction motor comprises the step of flux observation it is characterized in that described flux observation step comprises following a few step: carry out at first respectively that voltage model calculates and current model calculates magnetic linkage ψ _RhpfAnd ψ _Rlpf, the addition of two parts magnetic linkage is carried out rectangular coordinate/polar coordinate transform again and is obtained magnetic linkage angle θ then _sWith the magnetic linkage amplitude, magnetic linkage angle θ _sFeed back to again in the current model calculation procedure as parameter and to go.

2. the vector control method of induction motor according to claim 1 is characterized in that, described current model calculates and may further comprise the steps:

1) rotation transformation is according to the current i s and angle, the magnetic field θ of motor detection _sObtain the motor stator current i s under the alpha-beta coordinate system _α, is _β,

Is={is _α, is _β} ^T, calculate the motor-field current i s under the synchronous rotation d-q coordinate system then _d,

$\left[\begin{array}{c}{\mathrm{is}}_d\\ {\mathrm{is}}_q\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_s& {\sin \mathrm{\&theta;}}_s\\ {-\sin \mathrm{\&theta;}}_s& {\cos \mathrm{\&theta;}}_s\end{array}\right]\left[\begin{array}{c}{\mathrm{is}}_{\mathrm{\&alpha;}}\\ {\mathrm{is}}_{\mathrm{\&beta;}}\end{array}\right]$

Is _qBe the motor torque electric current;

2) electric current magnetic linkage Model Calculation is used above-mentioned motor-field current i s _dCalculate magnetic linkage ψ under the synchronous rotation d-q coordinate system _Rd,

${\mathrm{\&psi;}}_{\mathrm{rd}}=\frac{L_m}{1+{\mathrm{\&tau;}}_{r}s}{i}_{\mathrm{sd}}$

In the formula, τ _rBe rotor time constant, L _mBe the electric machine rotor mutual inductance;

3) magnetic linkage ψ under the above-mentioned d-q coordinate system is used in rotation inverse transformation _RdCarry out inverse transformation, calculate the magnetic linkage ψ under the alpha-beta coordinate system _r

4) low-pass filtering, by the second integral device, the measured value of when high speed current model being calculated filters,

Promptly obtain magnetic linkage ψ _Rlpf

3. the vector control method of induction motor according to claim 1 is characterized in that, described voltage model calculates and comprises following two steps:

1) back electromotive force calculates, and the voltage U s that current i s that detects according to motor and inverter send calculates counter electromotive force of motor e,

$\stackrel{\&OverBar;}{e}=\frac{L_r}{L_m}(\stackrel{\&OverBar;}{\mathrm{Us}}-\mathrm{Rs}\&CenterDot;\mathrm{is}-\mathrm{\&sigma;Ls}\frac{d}{\mathrm{dt}}\mathrm{is})$

In the formula, e is a counter electromotive force of motor, L _rBe rotor inductance, L _mBe the electric machine rotor mutual inductance, Rs is a motor stator resistance, L _sBe the rotor inductance, σ is a motor leakage inductance coefficient;

2) high-pass filtering, by first integrator, the measured value of when low speed voltage model being calculated filters, and promptly obtains magnetic linkage ψ _Rhpf,

4. the vector control method of induction motor according to claim 2 is characterized in that, described magnetic linkage addition and rectangular coordinate/polar coordinate transform process is the magnetic linkage ψ that voltage model calculates _RhpfMagnetic linkage ψ with electric current calculating _RlpfThe motor magnetic linkage that the process addition obtains observing

$\widehat{{\mathrm{\&psi;}}_r}={\mathrm{\&psi;}}_{\mathrm{rlpf}}+{\mathrm{\&psi;}}_{\mathrm{hpfr}},$ Therefore, the magnetic linkage computing formula of mixing is:

The magnetic linkage that calculates obtains magnetic linkage amplitude and magnetic linkage angle through rectangular coordinate/polar coordinate transform again,

${\mathrm{\&theta;}}_s=\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}.$

The magnetic linkage angle θ that calculates _sFeed back to rotation transformation and rotation inverse transformation as parameter.

5. the vector control apparatus of an induction motor comprises the flux observation module, it is characterized in that, described flux observation module comprises voltage model part, current model part, adder, rectangular coordinate/polar coordinate transform device and a feedback device.

6. the vector control apparatus of induction motor according to claim 5 is characterized in that, described current model partly comprises:

1) rotation transformation device is according to the current i s and angle, the magnetic field θ of motor detection _sObtain the motor stator current i s under the alpha-beta coordinate system _α, is _β,

Is={is _α, is _β} ^T, calculate the motor-field current i s under the synchronous rotation d-q coordinate system then _d,

$\left[\begin{array}{c}{\mathrm{is}}_d\\ {\mathrm{is}}_q\end{array}\right]=\left[\begin{array}{cc}\cos {\mathrm{\&theta;}}_s& {\sin \mathrm{\&theta;}}_s\\ {-\sin \mathrm{\&theta;}}_s& {\cos \mathrm{\&theta;}}_s\end{array}\right]\left[\begin{array}{c}{\mathrm{is}}_{\mathrm{\&alpha;}}\\ {\mathrm{is}}_{\mathrm{\&beta;}}\end{array}\right]$

Is _qBe the motor torque electric current;

2) electric current magnetic linkage Model Calculation device uses above-mentioned motor-field current i s _dCalculate magnetic linkage ψ under the synchronous rotation d-q coordinate system _Rd,

${\mathrm{\&psi;}}_{\mathrm{rd}}=\frac{L_m}{1+{\mathrm{\&tau;}}_{r}s}{i}_{\mathrm{sd}}$

In the formula, τ _rBe rotor time constant, L _mBe the electric machine rotor mutual inductance;

3) the rotation inverter uses magnetic linkage ψ under the above-mentioned d-q coordinate system _RdCarry out inverse transformation, calculate the magnetic linkage ψ under the alpha-beta coordinate system _r

4) low-pass filter, by the second integral device, the measured value with current model when high speed filters,

Promptly obtain magnetic linkage ψ _Rlpf

7. the vector control apparatus of induction motor according to claim 5 is characterized in that, described voltage model partly comprises:

1) back electromotive force calculation element, the voltage U s that current i s that detects according to motor and inverter send calculates counter electromotive force of motor e,

$\stackrel{\&OverBar;}{e}=\frac{L_r}{L_m}(\stackrel{\&OverBar;}{\mathrm{Us}}-\mathrm{Rs}\&CenterDot;\mathrm{is}-\mathrm{\&sigma;Ls}\frac{d}{\mathrm{dt}}\mathrm{is})$

In the formula, e is a counter electromotive force of motor, L _rBe rotor inductance, L _mBe the electric machine rotor mutual inductance, Rs is a motor stator resistance, L _sBe the rotor inductance, σ is a motor leakage inductance coefficient;

2) high pass filtering device by first integrator, obtains magnetic linkage ψ _Rhpf,

8. the vector control apparatus of induction motor according to claim 6 is characterized in that, described adder and rectangular coordinate/polar coordinate transform device, the magnetic linkage ψ of voltage model method _rWith current model method magnetic linkage ψ _RlpfThe motor magnetic linkage that the process adder obtains observing

$\widehat{{\mathrm{\&psi;}}_r}={\mathrm{\&psi;}}_{\mathrm{rlpf}}+{\mathrm{\&psi;}}_{\mathrm{hpfr}}$

Therefore, the magnetic linkage computing formula of mixed model is:

The magnetic linkage that calculates obtains magnetic linkage amplitude and magnetic linkage angle through rectangular coordinate/polar coordinate transform again,

${\mathrm{\&theta;}}_s=\mathrm{arctg}\frac{{\mathrm{\&psi;}}_{\mathrm{s\&beta;}}}{{\mathrm{\&psi;}}_{\mathrm{s\&alpha;}}}.$

Feedback device is with the magnetic linkage angle θ that calculates _sFeed back to rotation transformation device and rotation inverter as parameter.

Images