Robust MRAS Speed Observer and an Improved Zero-speed Position Estimation Design for Surface Permanent Magnet Synchronous Motor

Model Reference Adaptive System (MRAS) based techniques are one of the best methods to estimate the rotor speed and position due to its performances and straight forward stability approach. In this paper, we propose a new robust MRAS scheme based on sliding mode techniques to estimated the rotor speed of a Surface Permanent Magnet Synchronous Motor (SPMSM). Furthermore, an Estimator/Observer swapping system is designed to overcame position observability problems at zero speed which is an unobservable state point. The stability of the proposed observer is also discussed. Various tests are carried out in simulation to highlight the effectiveness and the robustness of the proposed rotor speed and position estimations design. Key–Words: Permanent magnet synchronous motor, Model reference adaptive system, Observer, Sliding mode