CN100420147C - Permasyn electric machine control system based on adaptive sliding moding structure - Google Patents

Abstract

This invention relates to a magnet synchronous motor control system based on an adaptive sliding mode structure composed of a primary circuit and a control circuit, in which, the control circuit includes a magnetic chain control ring, an inner ring for controlling the torque and an outer ring for controlling the rotation rate characterizing in adding a controller of sliding-mode structure in the outer ring of controlling rotation speed, which takes the rotation rate difference between the rotor angle speed and the given rotation rate as the input signals to output torque instruction control signals, which is used in the direct torque control of magnet synchronous motors.

Description

Control system for permanent-magnet synchronous motor based on adaptive sliding moding structure

Technical field:

The present invention relates to the Control of PMSM system.

Background technology:

Direct torque control (DTC) technology is a kind of high performance ac variable speed technology that grows up after vector control technology, gradually the research focus is transferred to the permagnetic synchronous motor that speed adjustable range is wider, efficient is higher (PMSM) in recent years and comes up.Compare with traditional vector control, DTC have control directly, computational process simplifies, do not need to carry out coordinate transform, do not need current regulator, characteristics such as directly switching states is carried out Optimal Control, the dynamic response of torque is fast, and the transducer that needs is few, and except that stator resistance, do not rely on other parameter of motor.But because the defective that PMSM DTC itself exists, have following problem in the control system: 1. magnetic linkage and torque pulsation are bigger.2. inverter switching frequency is non-constant.3. system is difficult to accurate control during low speed.Typical solution is to add pi regulator, but has also introduced when adding in the pi regulator direct torque control parameter of electric machine disturbance, shortcomings such as the responsive and poor robustness of load variations.

The control method of sliding moding structure is fit to non linear system very much, this control method is according to system's state at that time, constantly switch by controlled quentity controlled variable by certain control strategy, i.e. the variation that do not stop of the structure of system targetedly forces system to enter predefined sliding-mode surface and slides.After if system has entered the sliding formwork state, system parameters disturbance and external disturbance do not have effect to system, and the stability of system and dynamic quality only depend on the parameter of sliding-mode surface and sliding-mode surface thereof.Because sliding mode can design, and change with the parameter of system and external disturbance irrelevant, so strong robustness, reliability height.But up to now, the adaptive sliding moding structure control method is not applied in the direct torque control of permagnetic synchronous motor as yet.

Summary of the invention:

The present invention is for avoiding above-mentioned existing in prior technology weak point, a kind of control system for permanent-magnet synchronous motor based on adaptive sliding moding structure is provided, the adaptive sliding moding structure control method is used in the direct torque control of permagnetic synchronous motor, to improve the stability of a system, reliability and dynamic quality.

The technical scheme that technical solution of the present invention adopted is:

System of the present invention is made of main circuit and control circuit, and described control circuit comprises ring in magnetic linkage control ring, the torque control, and rotating speed control outer shroud;

Architectural feature of the present invention is to add the Sliding mode variable structure control device in described rotating speed control outer shroud, and described Sliding mode variable structure control device is in rotating speed control outer shroud, with rotor velocity ω and given rotating speed ω ^*Between speed discrepancy ω e be input signal, output torque instruction control signal T _e ^*, described input signal ω e and output torque instruction control signal T _e ^*The pass be:

$s\left(t\right)=C[-{\mathrm{\ω}}_e+{\∫}_0^t(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\ω}}_e\mathrm{dt}]$

$T_e^{*}=K{\mathrm{\ω}}_e+\mathrm{fsgn}\left[s\left(t\right)\right],K>0$

$\mathrm{sgn}\left[s\left(t\right)\right]=\left\{\begin{array}{cc}+1& s\left(t\right)>0\\ -1& s\left(t\right)<0\end{array}\right.$

C, K, f are adjustable parameter;

Design parameter f carries out parameter adaptive and is estimated as:

$\hat{f}=-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t\left|S\left(t\right)\right|\mathrm{dt},0<\mathrm{\&lambda;}<1$ λ is the self adaptation factor

Then control rate becomes $T_e^{*}={\mathrm{K\&omega;}}_e+[-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t|S\left(t\right)\left|\mathrm{dt}\right]\mathrm{sgn}\left[s\left(t\right)\right],K>0$

In the formula, J is a moment of inertia, B _wBe the viscous friction coefficient, T _eBe electromagnetic torque, ω is a rotor velocity, and ω e is a speed discrepancy, and s (t) is a sliding-mode surface, T _e ^*Be the torque control command;

Compared with the prior art, beneficial effect of the present invention is embodied in:

1, the present invention is by adding the Sliding mode variable structure control device in rotating speed control outer shroud, make speed discrepancy become state variable, be subjected to controller control and enter the sliding-mode surface slip, make stabilization of speed and change with the parameter of motor and external disturbance irrelevant, directly satisfy the purpose of permagnetic synchronous motor speed governing and anti-interference;

2, the present invention is provided with the Integral Sliding Mode face of band system parameters, the sliding-mode surface of this form is compared with traditional sliding-mode surface, the Integral Sliding Mode face design that has an electric system parameter can guarantee that the slip quantity of state all has robustness by initial time to the final moment, and allow nonlinear electric system be stabilized to asymptote, in a big way, have the disturbance rejection effect simultaneously.Add integration at feedforward loop circuit simultaneously and regulate, can reduce steady-state error.And it is short that the slip state enters the time of sliding-mode surface, and it is fast that electric system enters stable state;

If 3 customized parameter f are chosen as a bigger numerical value, not only can cause and buffet excessively, the radio-frequency component in also can activating system allows system's instability.Reduce to buffet when guaranteeing the condition of Integral Sliding Mode control, the present invention has adopted the auto-adaptive parameter estimation, and the uncertain border of estimating speed control system has in real time reduced the chattering phenomenon of sliding moding structure effectively;

4, in the traditional pi regulator direct torque control to the permagnetic synchronous motor parameter perturbation, load variations sensitivity and poor robustness.Sliding mode variable structure control device of the present invention is compared with pi regulator, has that very strong robustness is strong, reliability is high.Insensitive to the variation of electric system parameter, anti-uncertain disturbance ability is strong.

Description of drawings:

Accompanying drawing is a systematic schematic diagram of the present invention.

Below in conjunction with accompanying drawing, and the invention will be further described to pass through embodiment:

Referring to accompanying drawing, present embodiment is made of main circuit and control circuit, and main circuit is for from providing working power for motor after the DC power supply inversion of rectifier by inverter;

Control circuit is made of ring in magnetic linkage control ring, the torque control and rotating speed control outer shroud, wherein encircles structure setting routinely in magnetic linkage control ring and the torque control, comprises that ring is arranged on torque control command T in the torque control _e ^*The back, be used to suppress magnetic linkage and change influence rotary speed system, make rotating speed and magnetic linkage realize approximate decoupling zero; The magnetic linkage control ring is for keeping the constant of magnetic linkage amplitude, to guarantee to realize frequency control.

Rotating speed control outer shroud is used to make rotational speed omega to follow given rotating speed ω fast ^*Variation, adopt adaptive sliding moding structure control after, the difference ω e of the two enters sliding-mode surface and slides.The influence that not changed by system parameter variations and external disturbance.

In concrete the enforcement, the Sliding mode variable structure control device that is arranged in rotating speed control outer shroud is with rotor velocity ω and given rotating speed ω ^*Between speed discrepancy be ω e input signal, be output as torque instruction control signal T _e ^*, described input signal ω e and output torque instruction control signal T _e ^*The pass be:

$s\left(t\right)=C[-{\mathrm{\&omega;}}_e+{\&Integral;}_0^t(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\&omega;}}_e\mathrm{dt}]$

$T_e^{*}=K{\mathrm{\&omega;}}_e+\mathrm{fsgn}\left[s\left(t\right)\right],K>0$

$\mathrm{sgn}\left[s\left(t\right)\right]=\left\{\begin{array}{cc}+1& s\left(t\right)>0\\ -1& s\left(t\right)<0\end{array}\right.$

C, K, f are adjustable parameter;

Design parameter f carries out parameter adaptive and is estimated as:

$\hat{f}=-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t\left|S\left(t\right)\right|\mathrm{dt},0<\mathrm{\&lambda;}<1$ λ is the self adaptation factor

Then control rate becomes $T_e^{*}=K{\mathrm{\&omega;}}_e+[-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t|S\left(t\right)\left|\mathrm{dt}\right]\mathrm{sgn}\left[s\left(t\right)\right],K>0$

In the formula, J is a moment of inertia, B _wBe the viscous friction coefficient, T _eBe electromagnetic torque, ω is a rotor velocity, and ω e is a speed discrepancy, and s (t) is a sliding-mode surface, T _e ^*Be the torque control command;

Be provided with by prior art, the control loop of system of the present invention can be divided into three parts on function: first is a motor status observation link, i.e. magnetic flux shown in the figure and torque observe unit, this unit is according to voltage, electric current and speed feedback value, by corresponding algorithm ψ _f=∫ (u _s-i _sR _s) dt; T _f=1.5p _n(ψ _{S α}i _{S β}-ψ _{S β}i _{S α}) ask for torque value of feedback T _f, magnetic flux feedback value ψ _fWith magnetic linkage position signalling θ; Second portion is the comparison governing loop, and promptly value of feedback and set-point are relatively after the ring controller that stagnates forms torque adjustment signal T _Q, magnetic linkage conditioning signal ψ _Q, simultaneously by magnetic linkage position judgment unit output magnetic linkage angular position theta; Third part is that on off state is selected link, and by selecting corresponding on off state, the corresponding space vector of voltage of output is used to control permagnetic synchronous motor.Torque instruction signal T wherein _e ^*Produce after by speed error ω e, by motor speed is finally controlled in the control of changeing distance by the Sliding mode variable structure control device.

About the Sliding mode variable structure control device in the present embodiment:

One, the design of sliding-mode surface:

The mechanical dynamic equation of motor is: $\mathrm{\&omega;}=\frac{1}{\mathrm{JS}+B_w}(T_e-T_L)$

Turning to state equation is: $J\frac{\mathrm{d\&omega;}\left(t\right)}{\mathrm{dt}}=-B_w\mathrm{\&omega;}\left(t\right)+T_e\left(t\right)-T_L\left(t\right)$

Behind the abbreviation:

$\stackrel{.}{\mathrm{\&omega;}}=-\frac{B_w}{J}\mathrm{\&omega;}+\frac{1}{J}{T}_e-\frac{1}{J}{T}_L$

Make ω _e=ω ^*-ω

ω ^*Be rotary speed instruction, ω is an actual speed, and following formula becomes:

${\stackrel{.}{\mathrm{\&omega;}}}_e=-\frac{B_w}{J}{\mathrm{\&omega;}}_e-\frac{1}{J}{T}_e-\frac{1}{J}(-T_L-B_w{\mathrm{\&omega;}}^{*}-J{\stackrel{.}{\mathrm{\&omega;}}}^{*})$

Order $A=-\frac{B_w}{J}B=-\frac{1}{J}E=-T_L-B_w{\mathrm{\&omega;}}^{*}-J{\stackrel{.}{\mathrm{\&omega;}}}^{*}$

${\stackrel{.}{\mathrm{\&omega;}}}_e=A{\mathrm{\&omega;}}_e+B{T}_e+\mathrm{BE}---\left(1\right)$

If parameter A, B change, then: ${\stackrel{.}{\mathrm{\&omega;}}}_e=(A+\mathrm{\&Delta;A}){\mathrm{\&omega;}}_e+(B+\mathrm{\&Delta;B})T_e+\mathrm{BE};$ Can be changed into equally,

${\stackrel{.}{\mathrm{\&omega;}}}_e={\mathrm{A\&omega;}}_e+{\mathrm{BT}}_e+\mathrm{BE}+\mathrm{\&Delta;A}{\mathrm{\&omega;}}_e{+\mathrm{\&Delta;BT}}_e$

Make E '=E+B ^-1Δ A ω _e+ B ^-1Δ BT _eE ' is the broad sense disturbance

${\stackrel{.}{\mathrm{\&omega;}}}_e=A{\mathrm{\&omega;}}_e+{\mathrm{BT}}_e+{\mathrm{BE}}^{\&prime;}$

The design of suitable sliding-mode surface is to guarantee sliding moding structure strong robustness, the basis of good dynamic quality.The Integral Sliding Mode face can the Guarantee Status amount constantly all have robustness by initial time to final, allows uncertain dynamical system be stabilized to asymptote, and the disturbance rejection effect is strong in sizable scope.

According to this state equation (1) design Integral Sliding Mode face and sliding mode control strategy be:

$s\left(t\right)=C[-{\mathrm{\&omega;}}_e+{\&Integral;}_0^t(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\&omega;}}_e\mathrm{dt}]$

$T_e^{*}=K{\mathrm{\&omega;}}_e+\mathrm{fsgn}\left[s\left(t\right)\right],K>0$

$\mathrm{sgn}\left[s\left(t\right)\right]=\left\{\begin{array}{cc}+1& s\left(t\right)>0\\ -1& s\left(t\right)<0\end{array}\right.$

C, K, f are adjustable parameter;

Two, broad sense sliding formwork condition proves:

$\stackrel{.}{s}=C[-{\stackrel{.}{\mathrm{\&omega;}}}_e+(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\&omega;}}_e]$

$=C[\frac{B_w}{J}{\mathrm{\&omega;}}_e+\frac{1}{J}{T}_e^{*}+\frac{1}{J}E+(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\&omega;}}_e]$

$=C\left\{\frac{1}{J}\right[K{\mathrm{\&omega;}}_e+\mathrm{fsgn}\left(s\right)]+\frac{1}{J}E-\frac{K}{J}{\mathrm{\&omega;}}_e\}$

$=C\frac{1}{J}[\mathrm{fsgn}\left(s\right)+E]$

E＝-T _L-B _wω ^*-Jω ^*

$s\stackrel{.}{s}=\frac{C}{J}\left(f\right|s|+\mathrm{Es})=-\mathrm{CB}\left(f\right|s|+\mathrm{Es})$

C and B answer jack per line, $B=-\frac{1}{J}<0,$ C＜0 then

And f＞| E|, then $s\stackrel{.}{s}<0,$

Satisfy broad sense sliding formwork condition.Therefore, designed sliding mode satisfies existence and accessibility.

Three, auto-adaptive parameter is estimated:

Become condition that structure controller enters the sliding formwork state as can be known according to Integral Sliding Mode, parameter f must could guarantee broad sense sliding formwork condition greater than the absolute value of uncertain part E.As everyone knows, in the control of reality, the upper bound of whole uncertain part or lower bound be difficult to know, if parameter f is chosen as a bigger numerical value, not only can causes and buffet excessively, and the radio-frequency component in also can activating system allows system's instability.Reduce to buffet when guaranteeing the condition of Integral Sliding Mode control, adopted the auto-adaptive parameter estimation, in real time the uncertain border of estimating speed control system.If the upper bound of disturbance component E is greater than lower bound, the upper bound is f, f＞| E|,

Be the Estimation of its Upper-Bound value of E, the Sliding-Mode Control Based rule then becomes:

$T_e^{*}\left(t\right)=K{\mathrm{\&omega;}}_e\left(t\right)+\hat{f}\mathrm{sgn}\left[s\left(t\right)\right]$

Adaptive law is designed to:

$\hat{f}=\mathrm{\&lambda;CB}{\&Integral;}_0^t\left|S\left(t\right)\right|\mathrm{dt},0<\mathrm{\&lambda;}<1$

λ is the self adaptation factor

According to broad sense sliding formwork condition as can be known:

$s\stackrel{.}{s}=-\mathrm{CB}(\stackrel{-}{f}s+\mathrm{Es})\stackrel{-}{f}>\left|E\right|$ Must satisfy broad sense sliding formwork condition

$s\stackrel{.}{s}=-\mathrm{CB}\left(\stackrel{-}{f}\right|s|+\mathrm{Es}+\hat{f}|s|-\hat{f}|s\left|\right)$

$=-\mathrm{CB}\left(\hat{f}\right|s|+\mathrm{Es}-\hat{f}|s|+\hat{f}|s\left|\right)$

$=-\mathrm{CB}\left(\hat{f}\right|s|+\mathrm{Es})+\mathrm{CB}(\hat{f}-\stackrel{-}{f})\left|s\right|$

Order $\tilde{f}=\hat{f}-\stackrel{-}{f}$ Then $\mathrm{CB}(\hat{f}-\stackrel{-}{f})\left|s\right|=\mathrm{CB}\tilde{f}\left|s\right|$ Add the self adaptation factor lambda, then:

Order $\stackrel{.}{\stackrel{~}{f}}=\mathrm{CB}\left|s\right|$

Then $\stackrel{.}{\hat{f}}=\mathrm{CB}\left|s\right|$

$\hat{f}={\&Integral;}_0^t\mathrm{CB}\left|s\right|\mathrm{dt}$

$\hat{f}=\mathrm{\&lambda;}{\&Integral;}_0^t\mathrm{CB}\left|s\right|\mathrm{dt}$

Be easy to prove that this Adaptive Integral Sliding-Mode Control Based is at the Lyapunov function $\frac{1}{2}{s}^2+\frac{1}{2\mathrm{\&lambda;}}{\tilde{f}}^2$ Be stable down, so this auto-adaptive parameter is estimated to meet design requirement.

F is the upper bound of uncertain part;

It is uncertain part estimated value;

Be the poor of the estimated value of uncertain part and the upper bound; B is the electric system parameter; C be adjustable parameter should with system parameters B jack per line; E is the uncertain part of electric system; S is a sliding-mode surface.

Claims (1)

1. based on the control system for permanent-magnet synchronous motor of adaptive sliding moding structure, be made of main circuit and control circuit, described control circuit comprises ring and rotating speed control outer shroud in magnetic linkage control ring, the torque control;

It is characterized in that adding the Sliding mode variable structure control device in described rotating speed control outer shroud, described Sliding mode variable structure control device is in rotating speed control outer shroud, with rotor velocity ω and given rotating speed ω ^*Between speed discrepancy ω _eBe input signal, output torque instruction control signal T _e ^*, described input signal ω _eWith output torque instruction control signal T _e ^*The pass be:

$s\left(t\right)=C[-{\mathrm{\&omega;}}_e+{\&Integral;}_0^t(-\frac{B_w}{J}-K\frac{1}{J}){\mathrm{\&omega;}}_e\mathrm{dt}]$

$T_e^{*}=K{\mathrm{\&omega;}}_e+\mathrm{fsgn}\left[s\left(t\right)\right],K>0$

$\mathrm{sgn}\left[s\left(t\right)\right]=\left\{\begin{array}{cc}+1& s\left(t\right)>0\\ -1& s\left(t\right)<0\end{array}\right.$

C, K, f are adjustable parameter;

Design parameter f carries out parameter adaptive and is estimated as:

$\hat{f}=-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t\left|S\left(t\right)\right|\mathrm{dt},0<\mathrm{\&lambda;}<1$ λ is the self adaptation factor

Then control rate becomes $T_e^{*}=K{\mathrm{\&omega;}}_e+[-\mathrm{\&lambda;C}\frac{1}{J}{\&Integral;}_0^t|S\left(t\right)\left|\mathrm{dt}\right]\mathrm{sgn}\left[s\left(t\right)\right],K>0$

In the formula, J is a moment of inertia, B _wBe the viscous friction coefficient, T _eBe electromagnetic torque, ω is a rotor velocity, and ω e is a speed discrepancy, and s (t) is a sliding-mode surface, T _e ^*Be the torque control command.

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