Comparison of MRAS and SMO method for sensorless PMSM drives

Sensorless control is an important issue in permanent magnet synchronous motor (PMSM) under high reliability needed condition. Model of PMSM based sensorless control methods are suitable for medium and high speed region of the operation cycle. But, the parameter variation of PMSM restrict the application of the model based sensorless control. Two methods are compared for PMSM sensorless drives in this paper: model reference adaptive system (MRAS)and sliding mode observer (SMO). These methods are designed and simulated in MATLAB@SIMULINK software. The robustness of MRAS and SMO against parameter variation is analyzed and compared. The dynamic and static performance are also discussed for the two sensorless methods.