CN106712625A - Asynchronous motor control method based on internal model observer - Google Patents

Abstract

The present invention discloses an asynchronous motor control method based on an internal model observer. The method concretely comprises: reconstructing a control object estimation model, obtaining an asynchronous motor control current loop model, and designing an internal model controller according to the internal model control principle; designing a two-degree-of-freedom internal model controller on the basis of the obtained internal model controller; and designing an internal model observer on the basis of the asynchronous motor state equation, and finally matching the two-degree-of-freedom internal model controller and the internal model observer to realize the control of the asynchronous motor. According to the invention, the internal model observer is utilized into the two-degree-of-freedom internal model controller, the design of the internal model observer is closely linked to the control object estimation model, the control object estimation model comprises motor parameters, the uncertain disturbances such as model mismatching and parameter perturbation are existed in the motor operation process, and the internal model observer is led in and is employed to observe the disturbances to compensate the current loop so as to improve the system robustness.

Description

A kind of asynchronous motor control method based on internal model observer

Technical field

The invention belongs to variable frequency ac drive technical field, it is related to a kind of asynchronous motor control side based on internal model observer Method.

Background technology

In technical field of modern motor control, as vector control theory is constantly practical, by complicated asynchronous electricity Machine Mathematical Modeling carries out uneoupled control, and Vector Control System of Induction Motor technology is applied widely.

Vector Control System of Induction Motor method includes two parts of rotating speed outer shroud and current inner loop, and controller is typically from tradition PI controllers.Traditional PI controllers are easier to realize and be widely applied among electric machine control system with its simple structure.But Traditional PI controllers are easily influenceed by systematic parameter, there are problems that model mismatch, Parameter Perturbation, vulnerability to jamming, therefore right Some high performance control systems are difficult to reach desired performance requirement.

For the poor robustness that general Vector Control System for Asynchronous Machine changes to the parameter of electric machine, propose a kind of based in The Two Degree of Freedom Internal of mould observer.Two-Degree-of-Freedom Internal Model Control is the improvement to traditional internal model control, in tradition Mould control only one of which tunable filter parameter, can only between the tracking performance of system and Immunity Performance compromise, two from It is exactly one prefilter of increase on the basis of traditional internal mode controller by degree internal model, realizes system Immunity Performance and tracing property Can separate regulation.But traditional Two-Degree-of-Freedom Internal Model Control device cannot be eliminated effectively because model mismatch, Parameter Perturbation etc. bring Uncertain disturbances, so the present invention is on the basis of Two-Degree-of-Freedom Internal Model Control device, devise internal model observer to estimate Disturbance, so as to realize the precise control of electric current loop.

The content of the invention

It is an object of the invention to provide a kind of asynchronous motor control method based on internal model observer, traditional internal model is solved Control model mismatch, Parameter Perturbation, the problem of vulnerability to jamming difference for existing.

The technical solution adopted in the present invention is that a kind of asynchronous motor control method based on internal model observer is specifically pressed Following steps are implemented：

Step 1, designs internal mode controller：

Estimate mould by giving controlled device one estimation model for trying one's best consistent with controlled device of parallel connection, reconfigurable control object Type, obtains the model of asynchronous machine electric current loop, according to internal model control principle, with reference to the model of asynchronous machine electric current loop, designs Internal mode controller；

Step 2, designs Two-Degree-of-Freedom Internal Model Control device on the basis of the internal mode controller that step 1 is obtained；

Step 3, designs internal model observer on the basis of asynchronous machine state equation；

Step 4, the internal model observer obtained according to step 2 estimates current inner loop disturbance f_dAnd f_q, obtained according to step 2 Two-Degree-of-Freedom Internal Model Control device output torque voltage U_dWith excitation voltage U_q, and then obtain torque reference voltageEncouraged with reference Magnetoelectricity pressureRealize the control to asynchronous machine.

Feature of the present invention is also resided in,

Step 1, specially：

By giving controlled device one estimation model for trying one's best consistent with controlled device of parallel connection.Provide the control object of reconstruct Estimate model, i.e. the model of asynchronous machine electric current loop is：

In formula：R_s、R_rRespectively stator resistance and rotor resistance, ω_sIt is field synchronous angular velocity of rotation,It is magnetic leakage factor, L_s、L_r、L_mThe respectively stator inductance of induction machine, inductor rotor and rotor Between mutual inductance, s is differential operator.

Asynchronous machine electric current exports expression formula：

In formula：C (s) is internal mode controller, and G (s) is control target, G_nS () is the estimation model of controlled device, E (s) It is feedback error signal, R (s) is the input of control system, and Y (s) is the output of control system, and d (s) is exogenous disturbances；Pass through After closed loop feedback, system can effective disturbance suppression amount influence, improve antijamming capability；

According to internal model control principle, when Model Matching, i.e. G (s)=G_n(s), if taking internal mode controller for control is right Inverse as model, i.e., Design of Internal Model Controller is：

Step 2 is specially：The internal mode controller obtained to step 1 design increases a prefilter so that vulnerability to jamming Two-Degree-of-Freedom Internal Model Control device can be obtained with tracking performance separate regulation.

Step 3 is specially：

Mathematical Modeling under d-q phase orthogonal coordinate systems of the asynchronous machine after vector is：

In formula：u_sd、u_sqRespectively component of the stator voltage on d, q axle, i_sd、i_sqRespectively stator current is on d, q axle Component, ψ_sd、ψ_sqRespectively component of the stator magnetic linkage on d, q axle, ω₁It is field synchronous angular velocity of rotation；

Wherein, rotor current is ignored during motor operation, flux linkage equations are：

Make L=σ L_s, two formulas more than, and combine Parameter Perturbation and the interference of real system generation additive property, electric current loop Model can be expressed as again：

In formula：U_d、U_qIt is d-q phase stator voltages, Δ L, Δ R are systematic parameter undulate quantity；

The total Uncertainty of definition system is：

The design of internal model observer is completed, in formula：f_d、f_qThe Uncertainty of expression system.

Torque reference voltage in step 4With refer to excitation voltageExpression be for：

The beneficial effects of the invention are as follows interior during the present invention by internal model observer by applying to Two-Degree-of-Freedom Internal Model Control The design of mould controller is closely bound up with the estimation model of control object, and joins containing motor in the estimation model of control object , can there is the uncertain disturbances such as some model mismatches, Parameter Perturbation in motor operation course in number, by introducing internal model observer, Disturbance is observed using internal model observer, electric current loop is compensated, so as to improve system robustness.

Brief description of the drawings

Fig. 1 is the structured flowchart of control system of the present invention；

Fig. 2 is internal model control active feedback block diagram of the present invention；

Fig. 3 is Two-Degree-of-Freedom Internal Model Control block diagram of the present invention；

Fig. 4 is internal model observer control block diagram of the present invention.

Specific embodiment

With reference to the present invention is described in detail with specific embodiment.

The invention provides a kind of asynchronous motor control method based on internal model observer, using vector controlled, vector control System processed includes speed outer shroud and current inner loop two parts.As shown in figure 1, in order to in the two degrees of freedom based on internal model observer Mould control strategy is furtherd investigate on induction machine, and electricity in vector control system is instead of with Two-Degree-of-Freedom Internal Model Control device The PI controllers of ring are flowed, der Geschwindigkeitkreis use traditional PI controllers, of the invention on the basis of Two-Degree-of-Freedom Internal Model Control device, if Internal model observer is counted to realize current compensation.Specifically implement according to the following steps：

Step 1, sets up the model of asynchronous machine electric current loop, designs internal mode controller：

By giving controlled device one estimation model for trying one's best consistent with controlled device of parallel connection.Provide the control object of reconstruct Estimate model, i.e. the model of asynchronous machine electric current loop is：

In formula：R_s、R_rRespectively stator resistance and rotor resistance, ω_sIt is field synchronous angular velocity of rotation,It is magnetic leakage factor, L_s、L_r、L_mRespectively stator inductance, the mutual inductance between inductor rotor and rotor, S is differential operator.

Asynchronous machine electric current exports expression formula：

In formula：C (s) is internal mode controller, and G (s) is control target, G_nS () is the estimation model of controlled device, E (s) It is feedback error signal, R (s) is the input of control system, and Y (s) is the output of control system, and d (s) is exogenous disturbances.Pass through After closed loop feedback, system can effective disturbance suppression amount influence, improve antijamming capability.

According to internal model control principle, (disturbance is not considered) when Model Matching, i.e. G (s)=G_n(s), if taking internal model control Device processed is inverse for control object model, i.e., Design of Internal Model Controller is：

Wherein Reversible part in for object model, in order that control system canonical, Filter order is greater than equal to control object exponent number, therefore typically chooses low-pass first order filter.

Internal model control active feedback block diagram is as shown in Fig. 2 the relation between feedback controller M (s) and C (s) is：

Step 2, according to the Design of Internal Model Controller Two-Degree-of-Freedom Internal Model Control device that step 1 is obtained：

As shown in figure 3, increasing a prefilter by the internal mode controller described in step 1 so that vulnerability to jamming Can be with tracking performance separate regulation.System power is output as：

In formula：Two-Degree-of-Freedom Internal Model Control device design when, n should be chosen for so that Internal mode controller C₁(s)、C₂S minimum value that () can be realized.

The tracking performance and C of control system₁(s)、C₂S () is while correlation, interference free performance and C₂S () is related.Therefore, C can be designed according to system performance of noiseproof₂(s), in C₂(s) adjust it is excellent on the basis of, design C₁S () is good to obtain Input tracking performance.

Step 3, internal model observer of the design based on Two-Degree-of-Freedom Internal Model Control device：

Internal model observer system architecture is as shown in figure 4, L, M, P in block diagram are respectively matrix as described below, k₁、k₂For Regulation parameter.Mathematical Modeling under d-q phase orthogonal coordinate systems of the asynchronous machine after vector is：

In formula：u_sd、u_sqRespectively component of the stator voltage on d, q axle, i_sd、i_sqRespectively stator current is on d, q axle Component, ψ_sd、ψ_sqRespectively component of the stator magnetic linkage on d, q axle, ω₁It is field synchronous angular velocity of rotation.

Wherein, shown in flux linkage equations such as formula (8)：

Make L=σ L_s, can be obtained by formula (7) and formula (8)：

Formula (9) is arranged, can obtain its state equation is：

In formula：X=[i_d i_q]^T, v=[v_d v_q]^T,

Systematic parameter is depended on by the degree of accuracy of formula (9) visible model.When real system occurs the Parameter Perturbation of additive property During with interference, the state space equation of real system is expressed as again：

In formula：U_d、U_qIt is d-q phase stator voltages, Δ L, Δ R are systematic parameter undulate quantity.

The total Uncertainty of definition system is：

In formula：f_d、f_qThe Uncertainty of expression system.

Then the state space equation of real system is：

In formula：x_b=[f_q f_d]^T。

When the dynamic responding speed of internal model observer is far more than the speed that parameter is changed over time, it is believed that in control week In phase, the value of disturbance is constant, and its derivative is zero, i.e.,

By x_bUsed as extended mode variable, then the extended mode equation of system is：

On the basis of formula (14), construction internal model observer is：

In formula：

Disturbance observer is constructed by formula (15), its error dynamics equation is：

Understand to pass through design error state equation parameter K₁And K₂System Asymptotic Stability can be made, e levels off to zero.

Step 4, torque voltage U can be drawn by Two-Degree-of-Freedom Internal Model Control device in step 2_dWith excitation voltage U_q, it is above-mentioned to set The internal model observer of meter is estimated that torque disturbance f_dF is disturbed with excitation_q, as shown in system control block Fig. 1, become for 2r/2s The torque reference voltage for changingEqual to U_dAnd f_dSum, with reference to excitation voltageSimilarly.Expression formula is as follows：

A kind of asynchronous machine internal model control method of the present invention, including Two-Degree-of-Freedom Internal Model Control device and internal model observer, lead to Cross and give controlled device one estimation model for trying one's best consistent with control object of parallel connection, output valve and the estimation model of controlled device Output valve is poor, makees the input that the difference after difference feeds back to internal mode controller, withInternal mode controller is input to after making difference To suppress uncertain disturbance.Increase feedforward filter on the basis of traditional internal mode controller, construct Two-Degree-of-Freedom Internal Model control Device processed, Two-Degree-of-Freedom Internal Model Control device can realize system Immunity Performance and tracking performance separate regulation.Will in some high-performance Occasion is sought, Two-Degree-of-Freedom Internal Model Control device cannot meet Immunity Performance requirement, therefore increase internal model observer in electric current loop, and internal model is seen Surveying device can observe the uncertain disturbance of electric current loop, preferably compensation control be realized to electric current loop so that the stable state of electric current loop Fluctuation is smaller, so as to more accurately regulation motor angular speed.

Claims (5)

1. a kind of asynchronous motor control method based on internal model observer, it is characterised in that specifically implement according to the following steps：

Step 1, designs internal mode controller：

Estimate model by giving controlled device one estimation model for trying one's best consistent with controlled device of parallel connection, reconfigurable control object, The model of asynchronous machine electric current loop is obtained, according to internal model control principle, with reference to the model of asynchronous machine electric current loop, internal model is designed Controller；

Step 2, designs Two-Degree-of-Freedom Internal Model Control device on the basis of the internal mode controller that step 1 is obtained；

Step 3, designs internal model observer on the basis of asynchronous machine state equation；

Step 4, the internal model observer obtained according to step 2 estimates current inner loop disturbance f_dAnd f_q, two obtained according to step 2 Free degree internal mode controller output torque voltage U_dWith excitation voltage U_q, and then obtain torque reference voltageIt is electric with reference to excitation PressureRealize the control to asynchronous machine.

2. a kind of asynchronous motor control method based on internal model observer according to claim 1, it is characterised in that described Step 1, specially：

By giving controlled device one estimation model for trying one's best consistent with controlled device of parallel connection.The control object for providing reconstruct is estimated Model, i.e. the model of asynchronous machine electric current loop is：

$G_n\left(s\right)={\left[\begin{array}{cc}{\mathrm{\σsL}}_s+R_s& -{\mathrm{\ω}}_s{\mathrm{\σL}}_s\\ {\mathrm{\ω}}_s{\mathrm{\σL}}_s& {\mathrm{\σsL}}_s+R_s\end{array}\right]}^{-1}$

In formula：R_s、R_rRespectively stator resistance and rotor resistance, ω_sIt is field synchronous angular velocity of rotation,It is magnetic leakage factor, L_s、L_r、L_mRespectively stator inductance, the mutual inductance between inductor rotor and rotor, S is differential operator；

Asynchronous machine electric current exports expression formula：

$Y\left(s\right)=\frac{C\left(s\right)G\left(s\right)}{1+C\left(s\right)\[G\left(s\right)-G_n\left(s\right)\]}R\left(s\right)+\frac{1-C\left(s\right)G_n\left(s\right)}{1+C\left(s\right)\[G\left(s\right)-G_n\left(s\right)\]}d\left(s\right)$

In formula：C (s) is internal mode controller, and G (s) is control target, G_nS () is the estimation model of controlled device, E (s) is anti- Feedforward error signal, R (s) is input, and Y (s) is output, and d (s) is exogenous disturbances；By the way that after closed loop feedback, system can effectively suppress The influence of disturbance quantity, improves antijamming capability；

According to internal model control principle, when Model Matching, i.e. G (s)=G_n(s), if taking internal mode controller for control object model It is inverse, i.e., Design of Internal Model Controller is：

$C\left(s\right)=G_{n-}^{-1}\left(s\right)f_1\left(s\right).$

3. a kind of asynchronous motor control method based on internal model observer according to claim 1, it is characterised in that described Step 2 is specially：The internal mode controller obtained to step 1 design increases a prefilter so that Immunity Performance and tracking Performance separate regulation, obtains Two-Degree-of-Freedom Internal Model Control device.

4. a kind of asynchronous motor control method based on internal model observer according to claim 1, it is characterised in that described Step 3 is specially：

Mathematical Modeling under d-q phase orthogonal coordinate systems of the asynchronous machine after vector is：

$\left[\begin{array}{c}{u}_{sd}\\ u_{sq}\end{array}\right]=\left[\begin{array}{cc}{R}_s& 0\\ 0& R_s\end{array}\right]\left[\begin{array}{c}{i}_{sd}\\ i_{sq}\end{array}\right]+\frac{d}{dt}\left[\begin{array}{c}{\mathrm{\ψ}}_{sd}\\ {\mathrm{\ψ}}_{sq}\end{array}\right]+\left[\begin{array}{c}-{\mathrm{\ω}}_1{\mathrm{\ψ}}_{sq}\\ {\mathrm{\ω}}_1{\mathrm{\ψ}}_{sd}\end{array}\right]$

In formula：u_sd、u_sqRespectively component of the stator voltage on d, q axle, i_sd、i_sqRespectively stator current on d, q axle point Amount, ψ_sd、ψ_sqRespectively component of the stator magnetic linkage on d, q axle, ω₁It is field synchronous angular velocity of rotation；

Wherein, flux linkage equations are：

Make L=σ L_s,

$\left[\begin{array}{c}{U}_{sd}\\ U_{sq}\end{array}\right]=\left[\begin{array}{c}{R}_s{i}_{sd}-{\mathrm{\ω}}_1{\mathrm{\ψ}}_{sq}\\ R_s{i}_{sq}+{\mathrm{\ω}}_1{\mathrm{\ψ}}_{sd}\end{array}\right]+L\left[\begin{array}{c}\frac{{\mathrm{di}}_d}{dt}\\ \frac{{\mathrm{di}}_q}{dt}\end{array}\right]$

Two formulas more than, and combine real system Parameter Perturbation and the interference of additive property occur, current loop model can table again It is shown as：

$\left\{\begin{array}{c}{U}_d=-\left(L+\mathrm{\Δ}L\right){\mathrm{\ω}}_1{i}_{sq}+\left(L+\mathrm{\Δ}L\right)\frac{{\mathrm{di}}_{sd}}{dt}+\left(R_s+\mathrm{\Δ}R\right)i_{sd}\\ U_q={\mathrm{\ω}}_1\left(L+\mathrm{\Δ}L\right)i_{sd}+\left(L+\mathrm{\Δ}L\right)\frac{{\mathrm{di}}_{sq}}{dt}+\left(R_s+\mathrm{\Δ}R\right)i_{sq}\end{array}\right.$

In formula：U_d、U_qIt is d-q phase stator voltages, Δ L, Δ R are systematic parameter undulate quantity；

The total Uncertainty of definition system is：

$\left\{\begin{array}{c}{f}_d=-{\mathrm{\ΔL\ω}}_1{i}_{sq}+\mathrm{\Δ}L\frac{{\mathrm{di}}_{sd}}{dt}+{\mathrm{\ΔRi}}_{sd}\\ f_q={\mathrm{\ω}}_1{\mathrm{\ΔLi}}_{sd}+\mathrm{\Δ}L\frac{{\mathrm{di}}_{sq}}{dt}+{\mathrm{\ΔRi}}_{sq}\end{array}\right.$

The design of internal model observer is completed, in formula：f_d、f_qThe Uncertainty of expression system.

5. a kind of asynchronous motor control method based on internal model observer according to claim 1, it is characterised in that described Torque reference voltage in step 4With refer to excitation voltageExpression be for：

$\left\{\begin{array}{c}{U}_d^{*}=U_d+f_d\\ U_q^{*}=U_q+f_q\end{array}\right..$