MRAS based speed sensorless vector control of Induction Motor using Sliding mode Observer

This paper presents the speed estimation of vector controlled speed sensorless Induction motor (I.M.) using Model Reference Adaptive System (MRAS) and Sliding mode observer. At very low speed the dynamic and steady state performance of I.M. is not adequate due to mismatch of parameters of machine. The low speed performance of induction motor is improved by using MRAS and sliding mode observer. In the reference model of MRAS the sliding mode observer is placed and current model of Induction motor is used as adjustable model. The output of the reference model and adaptive model is compared and is given to adaption mechanism and it estimates the speed of vector control induction motor. The rotor flux MRAS is used to estimate the rotor speed of induction motor and is used as feedback signals for the vector controlled Induction motor.