Mechanical sensorless control of PMSM with on-line estimation of stator resistance

Sensorless control of PMSM is sensible to stator resistance uncertainties. In this paper, an on-line identification method of a sensorless controlled PMSM stator resistance is proposed. It is easy to implement and highly stable. A stability analysis based on the first method of Lyapunov shows the stability of the closed-loop system with the proposed estimator combined to the sensorless algorithm. This approach makes the sensorless control more robust with respect to the stator resistance variations at low speeds. The simulation and experimental results illustrate the validity of the analytical approach and the efficiency of the proposed method.