Discrete-time sliding mode approach for speed estimation of symmetrical and asymmetrical induction machines

This paper presents and analysis a rotor speed estimator for symmetrical and asymmetrical induction machines. The proposed scheme is based on discrete-time formulation of the sliding mode observer. The method is suitable to close-loop sensorless control of induction machines. The stability and parameter convergence of the proposed method are analyzed by using discrete-time likelihood Lyapunov. Experimental results based on DSP platform (TMS320F2812) are presented and they demonstrate the good performance of the proposed sensorless control scheme for symmetrical and asymmetrical induction motor drives.