Design and Hardware Implementation of Model Reference Adaptive System (MRAS) for Speed Control of Three-Phase Induction Motor
This paper presents a new predictive model reference adaptive system (MRAS) speed estimator for speed control of sensor-less induction motor (IM) drives. The specified estimator depends on the ﬁnite control set model predictive control (FCS-MPC) principle . A search-based optimization algorithm is used to calculate the rotor position which guarantees a minimum speed tuning error signal at each sampling period. This removes the need for a proportional–integral (PI) controller which is normally employed in the adaptation mechanism of MRAS estimators. Large number of experimental tests have been carried out to study the performance of the proposed estimator using a 1 HP IM with a ﬁeld-oriented control (FOC) scheme employed as the motor control strategy. Experimental results show improved performance of the MRAS scheme at low speeds and with different loading conditions. The proposed scheme also helps to improve the system rigidness against motor parameter variations and the maximum bandwidth of the speed loop controller increases.
Keywords - Induction Motor (IM) Drive, Vector Control, Speed Estimation, Model Reference Adaptive System (MRAS), Classical Rotor-flux MRAS, Proposed Predictive MRAS Control.