Sensorless Control for Permanent Magnet Synchronous Motor Using Sliding Mode Observer

This paper presents an approach of position sensorless control for permanent magnet synchronous motor (PMSM) based on a sliding mode observer. By using the DSP TMS320LF2407 to sample the real-time current of motor and dc-link voltage of inverter, and adopting mathematical model of PMSM in a stationary alphabeta reference frame, electromotive force is observed to achieve the real-time and on-line estimation of the position and speed of PMSM based on the principle of sliding mode observer. So the estimated position of rotor is continuously revised to keep the stator and rotor magnetic field being vertical and synchronous, and then closed loop operation of the motor is achieved. Theoretical analysis and simulation results show that the proposed strategy has stronger robustness and satisfying performance