1992 Volume 112 Issue 11 Pages 1047-1055
Vector-controlled induction motor drive without speed sensor has been widely studied. The speed estimation can be dealt with a problem of parameter estimation, based on the theory of MRAS (Model Reference Adaptive System). In such cases, the convergence and robustness of the system should be discussed. In this paper, we discuss the stability of the MRAS, which is constructed by a full-order adaptive observer of the induction motor and is used for estimating the rotor speed and identifying the stator resistance. It is verified that, under some conditions, the transfer matrix in the forward-path of MRAS is strictly positive real and the non-linear block in the feedback-path satisfies Popov's criterion. As theresult, the system is hyperstable. The influence of the set error of the rotor resistance is discussed and the design criterion for the feedback gain of the observer is given. Finally, the system is linearized for the parameter design of the speed estimator.