Speed Sensor-less Control of Induction Motors Based on Sliding-Mode MRAS Speed Estimation

The induction motor(IM) is a multi-variable, nonlinear and highly coupled system,according to the mathematical equations of IM,a sliding-mode(SM) model reference adaptive system(MRAS) observer for speed estimation in the sensor-less vector controlled induction motor system was proposed.The frame of the classic MRAS was adopted,a SM observer was used to as the feedback mechanism, and a scheme was discussed to avoid the pure integrators and a robust controller was proposed to adapt stator resistance variations.The proposed estimator was very robust and easy to tune to compare with the classical MRAS.The simulation results showed the validity of the developed methodologies.