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高等伺服控制報告
An Adaptive Sliding-Mode Observer for
Induction Motor Sensorless Speed Control
Dec, 2008
IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 41, NO. 4,
JULY/AUGUST 2005
Jingchuan Li, Longya Xu, Fellow, IEEE, and Zheng Zhang, Senior Member, IEEE
授課老師： 王明賢 教授
學 生 ： 楊智淵
南台科技大學電機系
Outline
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Abstract
I. INTRODUCTION
II. SLIDING-MODE CURRENT AND FLUX OBSERVER DESIGN
A. Current Observer I
B. Current Observer II
C. Rotor Flux Observer Design
III. ADAPTIVE SPEED ESTIMATION
IV. STABLITY ANALYSIS
V. SIMULATION RESULTS
A. Simulation Results by MATLAB
B. HIL Evaluation Results by TI 2812 DSP
VI. EXPERIMETAL RESULTS
VII. CONCLUSION
REFERENCES
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Abstract
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An adaptive sliding-mode flux observer is proposed for sensorless speed control of
induction motors in this paper.
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Two sliding-mode current observers are used in the method to make flux and speed
estimation robust to parameter variations.
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The adaptive speed estimation is derived from the stability theory
based on the current and flux observers
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The system is first simulated by MATLAB and tested by hardware-in-the-loop
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Simulation and experimental results are presented to verify the principles and
demonstrate the practicality of the approach.
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INTRODUCTION
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To make flux and speed estimation robust to parameter variations, a novel
adaptive sliding-mode flux and speed observer is proposed in the paper
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Two sliding-mode current observers are used in the proposed method
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The effects of parameter deviations on the rotor flux observer can be
alleviated by the interaction of these two current sliding-mode observers
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The stability of the method is proven by Lyapunov theory.
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An adaptive speed estimation is also derived from the stability theory.
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SLIDING-MODE CURRENT AND FLUX
OBSERVER DESIGN
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Defining stator currents and rotor fluxes as the state variables,we can
express the induction motor model in the stationary frame as
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The adaptive sliding-mode observer
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A. Current Observer I
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The first sliding-mode current observer is defined as
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According to the above formulas, the current error equation is
By selecting
large enough, the sliding mode will occur
, and then it follows that
From the equivalent control concept [8], if the current trajectories reach the sliding
manifold, we have
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B. Current Observer II
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The second sliding-mode current observer is designed differently from (3)
as
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By subtracting (1) from (6), the error equation becomes
From an equivalent control point of view, we have
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where
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C. Rotor Flux Observer Design
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Combining the results from (5) and (8), the rotor flux observer can be
constructed as
where L is the observer gain matrix to be decided such that the
observer is asymptotically stable.
From (5) and (8), the error equation for the rotor flux is
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III. ADAPTIVE SPEED ESTIMATION
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In order to derive the adaptive scheme, Lyapunov’s stability theorem is
utilized. If we consider the rotor speed as a variable parameter, the error
equation of flux observer is described by the following equation:
where
is the estimated rotor speed
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The candidate Lyapunov function is defined as
Where is a positive constant. We know that V is positive definite.
The time derivative of V becomes
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Let
be an arbitrary positive constant. With this assumption, the
above equation becomes
Letting the second term be equal to the third term in (14), we can find the following
adaptive scheme for rotor speed identification:
where
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In practice, the speed can be found by the following proportional and
integral adaptive scheme
Where
and
are the positive gains.
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IV. STABLITY ANALYSIS
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Since the second term is equal to the third term in (14), the time derivative
of becomes
It is apparent that (17) is negative definite. From Lyapunov stability theory, the
flux observer is asymptotically stable, guaranteeing the observed flux to
converge to the real rotor flux.
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V. SIMULATION RESULTS
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To evaluate the proposed algorithm for the rotor flux and
speed estimation, computer simulations have been conducted
using MATLAB.
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To further investigate the implemental feasibility, the
estimation and control algorithm are evaluated by hardware-inthe-loop (HIL) testing
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A. Simulation Results by MATLAB
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Fig. 3 shows the speed command, real speed, estimated speed, and
the speed estimation error
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Fig. 4 shows the real and estimated rotor flux and the flux estimation
error
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B. HIL Evaluation Results by TI 2812 DSP
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The control software is implemented and evaluated in real
time and can be debugged very easily in the absence of
motor.
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The control software can be easily transferred to the real
drive system with only minor changes.
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Fig. 7shows the motor step response to a speed command at 0.5 pu
( 900 r/min).
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Fig. 8 shows the real and estimated rotor flux and the estimated flux angle
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Fig. 9 shows the motor response to a trapezoidal speed command
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VI. EXPERIMETAL RESULTS
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VII. CONCLUSION
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A novel adaptive sliding-mode observer for sensorless speed
control of an induction motor has been presented in this paper
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The proposed algorithm consists of two current observers and
one rotor flux observer.
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The two sliding-mode current observersare utilized to
compensate for the effects of parameter variations on the rotor
flux estimation
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REFERENCES
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[1] C. Schauder, “Adaptive speed identification for vector control of induction
motors without rotational transducers,” IEEE Trans. Ind. Appl., vol.
28, no. 5, pp. 1054–1061, Sep./Oct. 1992.
[2] F. Z. Peng and T. Fukao, “Robust speed identification for speed-sensorless
vector control of induction motors,” IIEEE Trans. Ind. Appl., vol.
30, no. 5, pp. 1234–1240, Sep./Oct. 1994.
[3] Y. R. Kim, S. K. Sul, and M.-H. Park, “Speed sensorless vector control
of an induction motor using an extended Kalman filter,” in Conf. Rec.
IEEE-IAS Annu. Meeting, vol. 1, Oct. 4–9, 1992, pp. 594–599.
[4] H. Kubota, K. Matsuse, and T. Nakano, “DSP-based speed adaptive flux
observer of induction motor,” IEEE Trans. Ind. Appl., vol. 29, no. 2, pp.
344–348, Mar./Apr. 1993.
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REFERENCES
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[5] G. Yang and T. H. Chin, “Adaptive-speed identification scheme for
a vector-controlled speed sensorless inverter-induction motor drive,”
IEEE Trans. Ind. Appl., vol. 29, no. 4, pp. 820–825, Jul./Aug. 1993.
[6] A. Derdiyok, M. K. Guven, H. Rehman, N. Inanc, and L. Xu, “Design
and implementation of a new sliding-mode observer for speed-sensorless
control of induction machine,” IEEE Trans. Ind. Electron., vol. 49,
no. 5, pp. 1177–1182, Oct. 2002.
[7] H. Rehman, A. Derdiyok, M. K. Guven, and L. Xu, “A new current
model flux observer for wide speed reange sensorless control of an
induction machine,” IEEE Trans. Ind. Electron., vol. 49, no. 6, pp.
1041–1048, Dec. 2002.
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Thanks for your listening
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