Tracking control for sensorless induction motors with uncertain load torque and rotor resistance

In the rotor reference frame, the input-output linearization theory was adopted to decouple the rotor position and rotor flux. We then designed two adaptation laws to estimate the rotor resistance and mechanical parameters of the motor. The passive properties of the negative feedback connection from the rotor flux observer to the rotor resistance estimator, and the position controller were analyzed according to the passivity theorem. The overall control system was proved to be globally stable. Finally, experimental results show that the proposed scheme is robust to the variations of the rotor resistance and load torque disturbances. Furthermore, the estimated parameters can converge to the actual values.

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Adaptive Parameter Estimation and Position Control of Induction Motors Based on Passivity Theorem

Materials Science Forum ◽

10.4028/www.scientific.net/msf.626-627.489 ◽

2009 ◽

Vol 626-627 ◽

pp. 489-494

Author(s):

Jenn Yih Chen ◽

Bean Yin Lee

Keyword(s):

Position Control ◽

Induction Motors ◽

Current Model ◽

Gradient Algorithm ◽

Loop Current ◽

Feedback Connection ◽

Load Torque ◽

Flux Observer ◽

Rotor Resistance ◽

Rotor Flux

This paper presents the passivity-based rotor resistance and mechanical paramters estimation, and the position control for induction motors. Firstly, the input-output linearization theory is employed to decouple the rotor flux amplitude and the rotor position at the transient state. An open-loop current model flux observer then estimates the rotor flux. Furthermore, we adopted the gradient algorithm to design adaptive laws to estimate the rotor resistance, moment of inertia, viscous coefficient, and load torque. The passive properties of the feedback connection of the rotor flux observer to the rotor resistance estimator, and the position controller are analyzed by the passivity theorem. According to the properties, the overall control system is proved to be globally stable without using Lyapunov-type arguments. Finally, experimental results are provided to show that the proposed method is robust to variations of the mechanical parameters and load torque disturbances. Moreover, good position tracking response and parameters estimating characteristic can be obtained.

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Real-time implementation of MRAS rotor time constant estimation for induction motor vector control based on a new adaptation signal

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-03-2018-0133 ◽

2019 ◽

Vol 38 (1) ◽

pp. 287-303

Author(s):

Aymen Omari ◽

Bousserhane Ismail Khalil ◽

Abdeldjebar Hazzab ◽

Bousmaha Bouchiba ◽

Fayssal ElYamani Benmohamed

Keyword(s):

Vector Control ◽

Induction Motor ◽

Time Constant ◽

Induction Motors ◽

Experimental Results ◽

Field Oriented Control ◽

Load Torque ◽

Content Type ◽

Rotor Resistance ◽

The Stability

PurposeThe major disadvantage of the field-oriented control (FOC) scheme of induction motors is its dependency on motor parameter variations because of the temperature rise. Among the motor parameters, rotor resistance is a parameter that can degrade the robustness of FOC scheme. An inaccurate setting of the rotor resistance in the slip frequency may result in undesirable cross coupling and performance degradation. To overcome this disadvantage, the purpose of this paper is to propose a model reference adaptive system (MRAS) rotor time constant tuning to improve the induction motor drive performance and to compensate the flux orientation error in vector control law.Design/methodology/approachFirst, the dynamic model and the indirect field-oriented control of induction motor are derived. Then, an inverse rotor time constant tuning is proposed based on MRAS theory where a new adaptation signal formulation is used as reference model, and the estimated stator currents obtained from induction motors (IM) state space resolution is used in the adaptive model.FindingsThe effectiveness and robustness of IM speed control with the proposed MRAS inverse rotor time constant estimator is verified through MATrix LABoratory/Simulink model simulation and laboratory experimental results. The simulation and experimental results show good transient drive performances, satisfactory for rotor resistance estimation and robustness with regard to uncertainties and load torque disturbance.Originality/valueThis paper presents an online tuning of the inverse rotor time constant using a new adaptation signal MRAS model. The proposed estimator is proved to guarantee the stability for different operating conditions, especially in very low/zero speed region and heavy load torque. The stability analysis of the proposed estimation procedure is also demonstrated.

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